托福分類詞匯表

托福分類詞匯表托福分類詞匯表托福分類詞匯表托福分類詞匯表編制僅供參考審核批準生效日期地址：電話：傳真:郵編:

托福分類詞匯表（共17類863個常用單詞）

一、

psychology心理

1.

mental心理的2.

physical身體的，物質(zhì)的，物理的3.

spiritual心靈的4.

conformity從眾5.

majority多數(shù)人6.

minority少數(shù)人7.

thresholdjudgment（心理學）初始性判斷8.

subject受實驗對象9.

心理學psychology10.

心理現(xiàn)象mentalphenomenon11.

心理過程mentalprocess12.

心理狀態(tài)mentalstate13.

心理活動mentalactivity14.

意識consciousness15.

內(nèi)部活動internalactivity16.

普通心理學generalpsychology17.

實驗心理學experimentalpsychology18.

行為科學behavioralscience19.

心身關(guān)系mind-bodyrelation20.

遺傳heredity21.

活動理論activitytheory22.

中央處理器模型centralprocessormodel23.

信息儲存informationstorage24.

人工智能artificialintelligence,AI25.

計算機類比computeranalogy26.

計算機模擬computersimulation27.

計算機模型computermodel28.

測謊器liedetector29.

預(yù)期誤差anticipationerror30.

正誤法methodofrightandwrongcases31.

反應(yīng)response32.

訪談法interviewmethod33.

問卷法questionnaire34.

表情法methodofexpression35.

提示法anticipationmethod36.

視覺vision37.

瞳孔pupil38.

可見光visiblelight39.

顏色匹配colormatching40.

顏色對比colorcontrast41.

顏色混合colormixture42.

加色混合additivecolormixture43.

色弱colorweakness44.

紅色弱redweakness45.

色盲colorblindness46.

紅色盲redblindness47.

藍黃色盲blue-yellowblindness48.

內(nèi)耳innerear49.

中耳middleear50.

反映reflection

二、geography地理

1.

geography地理2.

geographer地理學家3.

hemisphere半球4.

meridian子午線，經(jīng)線5.

parallel平行圈，緯線6.

latitude經(jīng)度7.

longitude精度8.

elevation海拔9.

altitude高度10.

temperatelatitudes溫帶地區(qū)11.

horizon地平線12.

equator赤道13.

tropics熱帶地區(qū)14.

Arctic北極15.

Antarctic(Antarctica)南極16.

expedition探險17.

timezone時區(qū)18.

topography地形，地形學19.

plain平原20.

plateau(highland)高地21.

lowland低地22.

basin盆地23.

cavern(cave)洞穴24.

terrain地域25.

subterranean(underground)地底下26.

coastland沿海地區(qū)27.

island島嶼28.

continentalisland大陸島29.

volcanicisland火山島30.

coralisland珊瑚島31.

islet小島/ailit/32.

peninsular半島33.

continent大陸34.

continentalshelf大陸架35.

ranges山脈36.

valley峽谷37.

canyon峽谷38.

channel(strait)海峽39.

remote-sensing遙感的40.

terrestrial地球的，陸地的41.

terrestrialheat(geothermal)地熱42.

terrestrialmagnetism(geomagnetism)地磁43.

continentaldrift大陸漂移學說44.

sea-floorspreading海床擴展45.

evaporation蒸發(fā)46.

salinity含鹽度47.

oceanbottom海床48.

sediment沉淀物，沉積物49.

tropical熱帶的50.

temperate溫帶的51.

frigid寒帶的52.

formation形成53.

frostheaving凍脹現(xiàn)象54.

fieldstone卵石

三、geology地質(zhì)學

1.

geologist地質(zhì)學家2.

crust地殼3.

mantle地幔4.

core地核5.

continentalcrust大陸地殼6.

oceaniccrust海洋地殼7.

layer(stratum,復(fù)數(shù)strata)地層8.

plate板塊9.

fault斷層10.

faultplane斷層面11.

faultzone斷層帶12.

rift(crack;split)斷裂13.

disintegration(decomposition)分解,崩潰14.

erosion腐蝕15.

fossil化石16.

igneousrock火成巖17.

sedimentaryrock沉積巖18.

metamorphicrock變質(zhì)巖19.

quartz石英/kwa:ts/20.

limestone石灰?guī)r21.

marble大理石22.

granite花崗巖23.

lithogenous巖成的24.

lithosphere巖石圈25.

magma巖漿26.

mineral礦物27.

ore礦石28.

deposit礦床29.

platinum白金，鉑30.

silver銀31.

copper黃銅32.

aluminum鋁33.

tin錫34.

lead鉛35.

zinc鋅36.

nickel鎳37.

mercury汞，水銀38.

sodium鈉39.

gem寶石40.

diamond鉆石41.

emerald綠寶石42.

ruby紅寶石43.

glacier冰川44.

glacial冰川的45.

glacialepoch(age,period)冰川期46.

glacialdrift冰漬47.

iceberg冰山48.

volcano火山49.

activevolcano活火山50.

extinctvolcano死火山51.

dormantvolcano休眠火山52.

eruption火山噴發(fā)53.

crater火山口54.

lava火山巖漿55.

volcanic火山的56.

volcanicdust火山塵57.

volcanicash火山灰58.

earthquake(quake;tremor;seism)地震59.

seismic地震的60.

seismology地震學61.

magnitude震級62.

seismicwave地震波63.

cataclysm災(zāi)變

四、anthropologist人類學家

1.

paleoanthropologist古人類學家2.

ecologicalanthropologist生態(tài)人類學家3.

psychologicalanthropologist心理人類學家4.

origin起源5.

originate起源于6.

ancestor祖先7.

hominid人（科）8.

homogeneous同一種族（種類）的9.

tribe部落10.

clan氏族11.

archeologist考古學家12.

excavation挖掘13.

excavate(unearth)挖掘14.

ruins遺跡，廢墟15.

remains遺跡，遺骸16.

artifact手工藝品17.

relic遺物，文物18.

antique古物，古董19.

antiquity古代，古老20.

StoneAge石器時代21.

BronzeAge（青）銅器時代22.

IronAge鐵器時代23.

Paleolithic舊石器時代的24.

Mesolithic中石器時代的25.

Neolithic新石器時代的26.

archaeology考古學27.

anthropology人類學28.

morphology形態(tài)學29.

skull顱骨30.

cranial顱骨的

五、ecology生態(tài)學

1.

ecologist生態(tài)學家2.

ecosystem生態(tài)系統(tǒng)3.

balance(ofnature)自然界生態(tài)平衡4.

fauna動物群5.

flora植物群6.

rainforest雨林7.

foodchain食物鏈8.

acidrain酸雨9.

greenhouseeffect溫室效應(yīng)10.

infraredradiation紅外線輻射11.

ozonelayer(ozonosphere)臭氧層12.

ultravioletradiation紫外輻射13.

pollution污染14.

pollutioncontrol污染控制15.

airpollution空氣污染16.

waterpollution水污染17.

noisepollution噪音污染18.

soilpollution土壤污染19.

pollution-free無污染20.

pollutant污染物21.

noxious(toxic)有毒的22.

fumes（有毒）廢氣23.

waste廢物24.

solidwaste固體垃圾25.

sewage(wastewater)污水26.

sewagepurification污水凈化27.

sewagedisposal污水處理28.

decibel（噪音）分貝

六、meteorology氣象

1.

meteorology氣象2.

meteorologist氣象學家3.

forecast(predict)預(yù)報4.

climate氣候5.

atmosphere大氣層6.

troposphere對流層7.

current（氣）流8.

vapor蒸汽9.

evaporate蒸發(fā)10.

damp(wet;moist;humid)潮濕的11.

humidity濕度12.

moisture潮濕；水分13.

saturate飽和14.

dew露15.

frost霜16.

fog(mist)霧17.

smog煙霧18.

droplet小水珠19.

condense濃縮20.

crystal水晶體21.

downpour(torrentialrain)大雨22.

tempest(storm)暴風雨23.

drizzle細雨24.

shower陣雨25.

hail冰雹26.

blizzard(snowstorm)暴風雪27.

avalanche(snowslide)雪崩28.

precipitation（雨、露、雪等）降水，沉淀物，猛沖29.

breeze微風30.

gale大風/geil/31.

whirlwind旋風32.

typhoon臺風33.

hurricane颶風34.

tornado(twister,cyclone)龍卷風35.

funnel漏斗，漏斗云36.

disaster(calamity,catastrophe)災(zāi)難37.

devastation破壞，荒廢38.

submerge淹沒39.

drought旱災(zāi)

七、chemistry化學

1.

chemicalproperty化學特性，化學性質(zhì)2.

chemicalcomposition(makeup)化學成分3.

chemicalagent化學試劑4.

chemicalreaction化學反應(yīng)5.

chemicalchange化學變化6.

chemicalbond化學鍵7.

chemicalapparatus化學器械8.

substance(matter;material)物質(zhì)9.

element元素10.

periodictable周期表11.

hydrogen氫12.

oxygen氧13.

nitrogen氮14.

helium氦15.

carbon碳16.

calcium鈣17.

silicon硅18.

sulfur硫19.

iodine碘20.

compound化合物21.

hydrocarbon碳氫化合物22.

derivative衍生物23.

alchemy煉金術(shù)24.

petroleum(oil)石油25.

petroleumproducts石油產(chǎn)品26.

crudeoil原油27.

refine提煉，精煉28.

gasoline汽油29.

methane甲烷30.

solution溶液31.

dissolve溶解32.

solvent溶劑33.

solubility可溶性34.

cohesive聚合力35.

adhesive粘合力36.

atom原子37.

nucleus原子核38.

electron電子39.

neutron中子40.

proton質(zhì)子41.

molecule分子42.

particle粒子43.

ion離子44.

particleaccelerator粒子加速器45.

catalysis（復(fù)數(shù)catalyses）催化作用46.

catalyst催化劑47.

artificial人造的48.

synthetic合成的49.

syntheticfiber人造纖維50.

polymer聚合物51.

polymerization聚合作用52.

plastic塑料53.

dye染料54.

cosmetics化妝品

八、physics物理

1.

physics物理2.

mechanics力學3.

thermodynamics熱力學4.

acoustics聲學5.

electromagnetism電磁學6.

optics光學7.

dynamics動力學8.

force力9.

velocity速度10.

acceleration加速度11.

equilibrium平衡12.

statics靜力學13.

motion運動14.

inertia慣性15.

gravitation引力16.

relativity相對17.

gravity地心引力18.

vibration震動19.

medium(media)媒質(zhì)20.

frequency頻率21.

wavelength波長22.

pitch音高23.

intensity強度24.

echo回聲25.

resonance回聲，洪亮26.

sonar聲納27.

ultrasonics超聲學28.

electricity電29.

staticelectricity靜電30.

magnetism磁性，磁力31.

magnet磁體32.

electromagnet電磁33.

magneticfield磁場34.

electriccurrent電流35.

directcurrent(DC)直流電36.

alternatingcurrent(AC)交流電37.

electriccircuit電路38.

electriccharge電荷39.

electricvoltage電壓40.

electricshock觸電41.

electricappliance電器42.

conductor導(dǎo)體43.

insulator絕緣體44.

semiconductor半導(dǎo)體45.

battery(cell)電池46.

drybattery干電池47.

storagebattery蓄電池48.

electronics電子學49.

electronic電子的50.

electroniccomponent(part)電子零件51.

integratedcircuit集成電路52.

chip集成電器片，集成塊53.

electrontube電子管54.

vacuumtube真空管55.

transistor晶體管56.

amplification(名詞)放大57.

amplify（動詞）放大58.

amplifier放大器，揚聲器59.

oscillation震蕩60.

optical光（學）的61.

opticalfiber光學纖維62.

lens透鏡，鏡片63.

convex凸透鏡64.

concave凹透鏡65.

microscope顯微鏡66.

telescope望遠鏡67.

magnifier放大鏡68.

spectrum光譜69.

ultraviolet紫外線70.

XraysX射線71.

Gammaraysγ射線72.

infraredrays紅外線73.

microwaves微波74.

dispersion色散75.

transparent透明的76.

translucent半透明77.

opaque不透明的

九、mathematics

1.

mathematics數(shù)學2.

mathematician數(shù)學家3.

arithmetic算術(shù)4.

calculation計算5.

calculator計算器6.

abacus算盤7.

numeral數(shù)字8.

sum和9.

total(sumtotal)總和，總數(shù)10.

aggregate總計11.

fraction分數(shù)，小數(shù)12.

decimal十進位，（十進）小數(shù)13.

digit數(shù)字，數(shù)位14.

percentage百分比15.

addition加法16.

plus加上17.

subtraction減法18.

minus減去19.

multiplication乘法20.

multiplicationtable乘法表21.

multiply乘以22.

times乘以23.

power乘方24.

square平方25.

division除法26.

divide除以27.

algebra代數(shù)28.

quantity表示量的數(shù)（或符號）29.

equation方程式，等式30.

formula公式，慣例31.

root根32.

geometry幾何33.

geometric幾何的34.

dimension維35.

paralleladj.平行的n.平行線36.

quadrilateral四邊形37.

square正方形38.

area面積39.

rectangle長方形，矩形40.

polygon多邊形41.

cube立方形42.

volume體積43.

sphere球形44.

circle圓形45.

ellipse(oval)橢圓形46.

cone圓錐形47.

circumference圓周48.

diameter直徑49.

radius半徑50.

triangle三角形51.

angle角52.

degree(角)度53.

calculus微積分54.

differentialcalculus微分學55.

integralcalculus積分學56.

function函數(shù)57.

probability概率58.

statistics統(tǒng)計59.

quantitative量的，數(shù)量的60.

qualitative質(zhì)的，質(zhì)量的61.

deduction(inference)推論，演繹，扣除62.

induction歸納

十、agriculture農(nóng)業(yè)

1.

agriculture(farming)農(nóng)業(yè)2.

agricultural農(nóng)業(yè)的3.

land(soil)土壤；土地4.

soilconservation土壤保護5.

soilerosion泥土流失6.

silt粉砂，泥沙7.

clay黏土，濕土8.

clod土塊9.

agrarian土地的，農(nóng)業(yè)的10.

pilot(experimental)試驗性的11.

harrow(rake)耙，耙土12.

ridge田埂13.

furrow犁溝14.

plot（patch）小塊地15.

ranch農(nóng)場，牧場16.

plantation種植園17.

orchard果園18.

nursery苗圃19.

seedbed苗床20.

sickle鐮刀21.

spade鏟，鍬22.

shovel(平頭)鏟23.

pick稿24.

tractor拖拉機25.

cultivate(till)耕作26.

sow(seed)播種27.

harvest收割28.

weed除草29.

irrigate灌溉30.

manure(fertilizer)肥料31.

spray噴灑（農(nóng)藥）32.

insecticide(pesticide)殺蟲劑33.

pest害蟲34.

rust銹病35.

grain(cereal)谷物，谷粒36.

granary(grainstore)糧倉37.

mill碾，磨38.

wheat小麥39.

corn玉米40.

rice大米41.

barley大麥42.

sorghum高粱43.

oats燕麥44.

rye黑麥45.

millet粟，小米46.

vegetable蔬菜47.

horticulture園藝學48.

hydroponics水栽法，營養(yǎng)液栽培法49.

greenhouse(glasshouse,hotbed)溫室50.

cabbage洋白菜51.

lettuce生菜52.

mustard芥菜53.

spinach菠菜54.

broccoli花椰菜55.

cucumber黃瓜56.

eggplant茄子57.

pepper辣椒58.

pumpkin南瓜59.

tomato西紅柿60.

beet甜菜61.

carrot胡蘿卜62.

radish小紅蘿卜63.

pea豌豆64.

soybean大豆65.

celery芹菜66.

garlic大蒜67.

leek韭菜68.

onion洋蔥頭69.

potato土豆70.

peanut花生71.

sesame芝麻72.

cotton棉花73.

husbandry(animal，husbandry)畜牧業(yè)74.

pasture牧場75.

livestock家畜76.

fowl(poultry)家禽77.

cattle牛，家畜78.

buffalo野牛79.

dairy(dairycattle)奶牛80.

dairyfarm乳牛場81.

hay（作飼料用）干草82.

haystack干草堆83.

fodder(feed)飼料84.

trough飼料槽85.

barn(shed)牲口槽86.

stable廄，馬廄87.

cowshed牛棚88.

pigpen(hogpen,pigsty)豬圈89.

sheepfold(sheeppen)羊欄90.

roost(henhouse)雞舍91.

fishfarm養(yǎng)魚場92.

aquaculture水產(chǎn)養(yǎng)殖

十一、animal動物

1.

Darvinism達爾文學說2.

naturalselection自然選擇3.

class綱4.

order目5.

family科6.

genus屬7.

suborder亞目8.

species種9.

invertebrate無脊椎動物10.

vertebrate脊椎動物11.

aquatic(life)水生動物12.

reptile爬行動物13.

amphibian(amphibiousanimal)兩棲動物14.

dinosaur恐龍15.

bird鳥類16.

extinction滅絕17.

mammal哺乳動物18.

primates靈長目動物19.

insect昆蟲20.

antenna(復(fù)數(shù)antennae)觸須21.

larva幼蟲，幼體22.

camouflage偽裝23.

pest害蟲24.

worm蟲，蠕蟲25.

hibernate冬眠26.

lizard蜥蜴27.

chameleon變色蜥蜴28.

regeneration再生29.

turtle龜30.

beast野獸31.

domesticate馴養(yǎng)32.

predatory(carnivorous)食肉的33.

predator捕食者34.

prey（動詞）捕食（名詞）被捕食的動物35.

scavenger食腐動物36.

migrate遷移37.

wing翅膀，翼38.

bill（鳥）嘴39.

beak（鷹等的）嘴40.

nest筑巢41.

dolphin海豚42.

whale鯨魚43.

bat蝙蝠44.

gorilla大猩猩45.

chimpanzee黑猩猩46.

habitat棲息地47.

rodent嚙齒動物（如松鼠）48.

primate靈長動物49.

plankton浮游生物50.

mollusk軟體動物51.

coelenterate腔腸動物（如珊瑚）52.

shrimp小蝦53.

prawn對蝦54.

lobster對蝦55.

crab螃蟹56.

clam蛤蜊57.

sponge海綿58.

coral珊瑚59.

starfish海星60.

canary金絲雀61.

chirp(鳥，蟲的叫聲)唧唧62.

squeak（老鼠等）吱吱63.

porpoise海豚64.

sloth樹懶65.

slothful懶惰的66.

hygiene衛(wèi)生67.

sanitation衛(wèi)生68.

parasite寄生蟲69.

moth蛾70.

caterpillar毛蟲71.

hordes(昆蟲等)群72.

swarms(昆蟲等)群73.

flock（鳥，羊等）群74.

community動物的群落或人的部落75.

herd獸群76.

bunch（花等）束，捧77.

beaver海貍78.

monogamous一夫一妻的，一雄一雌的79.

polygamous一夫多妻的，一雄多雌的80.

polyandrous一妻多夫的，一雌多雄的81.

trapper誘捕動物者82.

rhinoceros犀牛83.

niche小生態(tài)環(huán)境84.

vestige退化器官，遺跡85.

oyster牡蠣86.

fertilizer使…受精87.

larvae幼蟲88.

tentacle觸角89.

homotherm恒溫動物90.

poikilotherm變溫動物91.

metabolism新陳代謝92.

baboon狒狒93.

breed(名詞)品種，（動詞）繁殖94.

multiply（reproduce）繁殖95.

hatch孵96.

spawn(魚、蝦、蛙等)孵97.

offspring(young)解剖學98.

anatomy解剖學99.

appetite食欲生物微生物食草的食肉的雜事的

十二、plant植物

1.

botany植物學2.

botanist植物學家3.

botanical(botanic)植物的4.

plant植物5.

aquaticplant水生植物6.

parasiteplant寄生植物7.

root根8.

canopy樹冠層，頂棚9.

foliage(leaf)葉10.

leaflet小葉11.

rosette(葉的)叢生12.

stem莖13.

stalk桿14.

leafstalk葉柄15.

shoot(sprout)嫩芽，抽枝16.

flower花17.

bud花蕾18.

petal花瓣19.

peel(skin)果皮20.

shell(硬)果殼21.

husk（干）果殼；（玉米）苞葉22.

trunk樹干23.

branch樹枝24.

bough大或者粗的樹枝25.

twig小樹枝26.

bark樹皮27.

jungle叢林28.

lawn草坪29.

meadow草地，牧場30.

prairie大草原31.

shrub(bush)灌木32.

cluster一簇（灌木）33.

fern蕨類植物34.

herb草35.

photosynthesis光合作用36.

symbiosis共生37.

wither(shrivel,fade)凋謝38.

pollen花粉39.

pollinate傳授花粉40.

pollination授粉41.

cell細胞42.

tissue組織43.

organ器官44.

system系統(tǒng)45.

seeds種子46.

everlasting永久的47.

orchid蘭花48.

pollinate授粉49.

crossbreed雜交50.

shrub灌木51.

sequoia紅杉52.

rootpressure根壓53.

cohesion-tension凝聚壓力54.

bore腔，腸55.

column花柱56.

symbiotic共生的57.

immunity免疫58.

organism生物，有機物59.

necrosis壞死60.

barren貧瘠61.

futile無用的62.

carbohydrate(starch)碳水化合物（淀粉），糖類63.

glucose葡萄糖64.

starch淀粉65.

fat脂肪66.

protein蛋白質(zhì)67.

vitamin維他命68.

calorie卡路里（熱量單位）69.

malnourished營養(yǎng)不良的70.

nutrition營養(yǎng)

十三、politics政治

1.

constitution憲法2.

legislation立法3.

Democrats民主黨4.

Republicans共和黨5.

Amendment修正案6.

Congress美國國會7.

Senate參議院8.

HouseofRepresentatives眾議院9.

monarchy君主制10.

anarchism無政府主義11.

federalsystem聯(lián)邦制12.

presidentialsystem總統(tǒng)制13.

municipal市的，市政的14.

metropolitan大都市的15.

centralized中央集權(quán)的16.

ideology意識形態(tài)17.

maneuver策略，演習18.

tariff關(guān)稅19.

immigrant移民20.

institutionalize機構(gòu)化21.

election選舉22.

vote投票23.

officeholding任職24.

veto否決25.

AmericanRevolution美國革命/獨立戰(zhàn)爭26.

IndependenceWar美國獨立戰(zhàn)爭27.

AmericanCivilWar美國內(nèi)戰(zhàn)28.

radical激進的,根本的29.

overturning顛覆性的30.

independent獨立的31.

breathtaking激動人心的32.

military軍事的33.

colonize拓殖，殖民34.

percapita人均35.

treason叛國36.

conspiracy陰謀37.

imprisonment監(jiān)禁38.

release釋放39.

pardon特赦40.

accusation譴責，指控41.

welfare福利42.

patronage資助，贊助43.

unionization聯(lián)合，結(jié)合

十四、education教育

1.

educator教育家2.

highereducation高等教育3.

moralcharacter道德品質(zhì)4.

domain領(lǐng)域5.

faculty全體教員6.

alumni校友7.

treasurer生活委員，財務(wù)大臣8.

electivesystem選課制度9.

curriculum課程（總稱）10.

discipline學科，管理11.

learnbyrote死記硬背

十五、music音樂

1.

musicalinstrument樂器2.

orchestra樂隊3.

string弦樂4.

wind管樂5.

shookrattle搖撥浪鼓6.

pounddrum擊鼓7.

footbeat點腳，跺腳8.

percussion震蕩，打擊樂器9.

note音符10.

score樂譜11.

movement樂章12.

fanatical狂熱的13.

hillbillymusic鄉(xiāng)村音樂14.

folkmusic民間音樂15.

popmusic流行音樂16.

classicalmusic古典音樂17.

Jazz爵士樂

十六、

astronomy天文

1.

astronomy天文學2.

astronomical天文的3.

astronomicalobservatory天文臺4.

astronomer天文學家5.

astrophysics天文物理學6.

astrology占星學7.

pseudoscience偽科學8.

cosmos(universe)宇宙9.

cosmology宇宙學10.

infinite無限的11.

cosmic宇宙的12.

cosmicradiation宇宙輻射13.

cosmicrays宇宙射線14.

celestial天的15.

celestialbody(heavenlybody)天體16.

celestialmap(skyatlas)天體圖17.

celestialsphere天球18.

dwarf(dwarfstar)矮星19.

quasar類星體，類星射電源20.

constellation星座21.

galaxy(MilkyWay)新河系22.

cluster星團23.

solarsystem太陽系24.

solarcorona日冕25.

solareclipse日食26.

solarradiation太陽輻射27.

planet行星28.

planetoid(asteroid)小行星29.

revolve旋轉(zhuǎn)，繞轉(zhuǎn)30.

twinkle閃爍31.

nakedeye肉眼32.

Mercury水星33.

Venus金星34.

Earth地球35.

Mars火星36.

Jupiter木星37.

Sa