21. You can not imagine how much I ______ on this dress. Is it beautiful?
A. paid B. took C. cost D. spent
[剖析] 答案为D。本题考察四个表“花费”的动词辨析。主语为人，且和介词on搭配的动词是spend。
22. ---- Do you know _____ university student who is talking with Joe?---- Yes， she，s my cousin, Kate.
A. a B. an C. the D. /
[剖析] 答案为C。university虽然以元音字母u开头，但其前若使用不定冠词时，则要用a.不过此题中不能使用不定冠词，而是特指和Joe说话的那个大学生，故要选the。
23. The number of giant pandas is getting ______ because their living areas are becoming farmlands.
A. less and less B. larger and larger C. smaller and smaller D. fewer and
fewer
[剖析] 答案为C。句意为“大熊猫的数量越来越少因为他们的生存空间正逐渐变成农场”。本题中四个选项都是“比较级+ and + 比较级”的结构，表示“越来越……”。主语为number，只能和large或small搭配。而结合句意可判断答案为C。
24. Be careful when you come _______ the street，because the traffic is very busy
at the moment.A. across B. behind C. between D. over
[剖析] 答案为A。本题考察方位介词的用法。“过马路”一般为表面横穿，因此要用across。
25. ---- Do you often clean your classroom?---- Yes, our classroom ______ every day.
A. clean B. cleans C. is cleaned D. Cleaned
[剖析] 答案为C。句中有every day，主语为our classroom，故要用一般现在时的被动语态。