2. What was scientists‘ understanding of cryptic species？

　　A They occurred in equal numbers in all biogeographical regions.

　　B They were mostly found in insects find reptiles.

　　C They were likely to be in tropical rather than temperate regions.

　　D Both B and C.

　　3. Do scientists know how many cryptic species exist？

　　A Not yet.

　　B Yes，they do.

　　C They will know the answer in another one or two years;

　　D They will never know the answer.

　　4. Which of the following about the African bush elephant and the African elephant is true？

　　A The WCU are interbreeding those elephants.

　　B They are interbreeding species.

　　C They are two genetically distant species.

　　D They depend on each other for survival.

　　5. People were confused in their attempts to control malaria in Europe in the early1900s，because scientists

　　A identified only one mosquito species instead of six species.

　　B thought only three mosquito species transmitted disease.

　　C thought there was only one mosquito species.

　　D did not know what species was being studied.

　　答案與題解：

　　1. D 短文的第一段第二句的大意是，研究結果為廣泛的研究領域提供啟示，包括生物多樣性研究，還能幫助我們理解傳染疾病及其演變。所以，選項A、B、C都是正確的，它們不是答案。選項D的“適者生存”的內容文章中沒有提及，因此是本題的答案。

　　2. D 短文的第二段第二句描述的是科學家目前的研究結果，第三段描述的是科學家在這之前對于cryptic species的理解。本題用的是過去式，問的是過去的狀況，因此，答案在第三段中，B和C是答案，所以D是正確選擇。

　　3. A 第三段和第五段提供了答案。第三段的倒數第二句中的Until.……no one will know just how many cryptic species exist.其意思就是人們目前還不了解。第五段的最后一句也說明了研究者目前對此尚未了解。

　　4. C 答案在第六段中。該段舉了非洲大象為例，說明什么是cryptic species.第六段的句子“A 2001 study found the elephants were actually two genetically distinct，non- interbreeding spemes”是選擇C的依據。選項A不對，the WCU并沒有雜交繁殖這兩種象。選項B不對，短文說這兩種象是非雜交物種。選項D的內容短文中找不到。

　　5. A 短文最后一段告訴我們，由于對蚊子種類不了解，20世紀初期瘧疾曾肆虐歐洲，最終，科學家才了解到蚊子這一物種不是由一個種類而是由六個種類組成。所以，應該選擇A.