26. Lucy usually cleans the cage every two days. (对画线部分提问)_ _______ Lucy usually clean the cage?
[剖析] 答案为How often does。对every two days提问要用how often。
27. I didn't understand __________，so I raised my hand to ask...
A. what my teacher says B. what does my teacher say C. what my teacher said D. what did my teacher say
[剖析] 答案为C。本题为宾语从句，由于需要用陈述语序可排除B、D;另外，主句时态为一般过去时，则从句也要用对应的过去时态，故还可排除A。
28. ---- How much ______ the shoes? ---- Five dollars ______ enough.
A. is;is B. are;is C. are;are D. is;are
[剖析] 答案为B。shoes作主语时，谓语动词应用复数形式;five dollars是一个整体，应按单数对待。
29. 误〕 We got to the top of the mountain in daybreak. 〔正〕 We got to the top of the mountain at day break.
〔析〕 at用于具体时刻之前，如：sunrise, midday, noon, sunset, midnight, night。
30. 〔误〕 Dont sleep at daytime 〔正〕 Dont sleep in daytime.
〔析〕 in 要用于较长的一段时间之内，如：in the morning / afternoon, 或 in the week / month / year. 或 in spring / supper /autumn / winter等等。