1. [由此及彼]根據(jù)詞根含義推測同根詞的含義。
microbial a.微生物的→① microbiology n.
→② microbiologist n.
2. [望文生義]根據(jù)詞根和詞綴知識寫出下列單詞的含義。
① microbe n.（提示：be是bi的異體）
② microbian a.（提示：-an=of）
3. [同義相連]將左欄的單詞和右欄中相對應的中文含義連接起來。
① bioclean a.生物地理學
② bioclimatolgy b.無菌的
③ bioelectricity c.生物氣候?qū)W
④ biogeography d.生物工藝學
⑤ biosphere e.生物電流
⑥ biotechnique f.生物圈
4. [尋根問底]指出下列單詞的詞根并領會其詞義的由來。
① amphibian n.兩棲動物（或植物）
amphibious a.兩棲的（提示：amphi-=both）
② macrobian n.長壽的人；
macrobiotics n.長壽法（提示：macro-=great）
③ biotic a.生物的；生命的
④ biogenesis n.生源說
⑤ biometrics n.生物統(tǒng)計學
biometrician n.生物統(tǒng)計學家
⑥ bionomy n.生理學；生態(tài)學
bionomics n.（個體）生態(tài)學（提示：nom=law）
⑦ epibiotic n.體外生的（提示：epi-=upon, out）
⑧ bioplasm n.原生質(zhì)
10. cad, cas, cid [L]=to fall, to befall降，降臨
cad，cas，cid是同源異形詞根，都源于拉丁動詞cadere，意思相當于to fall（降落）或to befall（降臨）。其中，cad 是不定式詞干，cas是動名詞詞干，而cid是cadere的異體cidere的不定式詞干。這族同根詞的數(shù)量較大。
decadent [de-=down下；cad=to fall降；-ent a.=-ing表性質(zhì)→“falling down下降的”] a. falling down morally;falling into ruin墮落的；頹敗的：The Ching Empire had become decadent by that time.當時清帝國已經(jīng)腐敗了。
▽decadence [de-;cad;-ence n.] n.衰落；頹廢
case [cas=to befall降臨；-e→“that which befalls降臨之事”→] n. event;condition事件；情況：a typical case典型事件
casual [cas=to befall降臨；-u-;-al a.=having the quality有……性質(zhì)的→“having the quality of befalling, or happening by chance帶有偶發(fā)性質(zhì)的”→] a.① not planned偶然的：a casual meeting巧遇 ② infor-mal非正式的：casual clothing便服
▽casualty [casual;-ty n.] n.事故的傷亡者
occasion [oc-（ob-）=in the way of在……面前；cas=to befall降臨；-ion n.=the state or result表狀態(tài)或結(jié)果→“that which befalls in one's way降臨在面前的事”→] n.① instance or case情況② favorable time, or opportunity時機；機會：as occasion serves一旦有適當?shù)臋C會
▽occasional [occasion;-al a.] a.偶爾的
accident [ac-(ad-)=towards朝向；cid=to befall降臨；-ent n.=thing事→“thing that befalls towards a person朝著某人降臨的事”→] n. ①unexpected event意外的事；偶然的事：I met her quite by accident.我碰到她是很偶然的事。② unfortunate happening事故：traffic acci-dents交通事故
▽accidental [accident;-al a.] a.意外的；偶然的
incident [in-=on, upon在……上；cid=to befall發(fā)生；-ent n.=thing事→“thing that befalls on a particular person or happens at a particular time發(fā)生在某人身上或某個時刻的事”→] n. event, or occurence事件；事變：the July 7th Incident 七七事變
▽incidental [incident;-al a.] a.偶然的；伴隨的
incidence [in-;cid;-ence n.] n.發(fā)生；發(fā)生率
coincide [co-（com-）=together共同；in-=upon在……之上；cid=to befall降臨→“to befall upon together共同降臨在……之上”] v. ①happen at the same time or same place（時間、空間）恰好相合：My birthday coincides with yours. 我恰好和你同一天生日。② agree;correspond一致；符合：to coincide in opinion意見相符
▽coincident [coincid(e);-ent a.] a.同時發(fā)生的；一致的
deciduous [de-=off脫離；cid=to fall降；-u-;-ous a.=having the quality有……性質(zhì)的→] a. having the quality of falling off at a certain time定期脫落的：deciduous trees落葉林
occident [oc-（ob-）=down下；cid=to fall降落；-ent n.=thing connected with 表相關(guān)事物→“the direction towards which the heavenly bodies were supposed to fall down前人認為的天體降落的方向”→] n.① the west西方② the western hemisphere西半球：the Occident亞洲以西的全部國家；歐洲；歐美
▽occidental [occident;-al a.] a.西方的
decay [de-=down下；cay（cad的變形）=to fall降→] v. fall down from a state of health and excellence;rot衰退；腐朽：The old man's teeth are all decayed.這老人的牙齒全壞了。
