Unit 4 Learning efficiently
解析：該賓語從句描述“想象”與“現實”之間的差距，也是與現在事實不符的虛擬語氣。故選c。
3. 虛擬語氣在as if(though) /even if(though)等句子中的使用
we should act as if she were watching us.我們要表現出好像她在看著我們。
i couldn’t help even though i had been there at the moment.即使我當時在場，我也沒有辦法。
4. 虛擬語氣在it is important/ necessary/ desirable/ possible/ natural/ essential that-clause以及would rather/sooner后的從句中和其他的特殊結構中的使用。比如：
it’s necessary that you (should) keep your safety belt on at all times 你有必要始終系好安全帶。
it’s strange that they (should) feel so angry.真奇怪，他們感到那么生氣。
it’s a pity that they should have forgotten to tell you about it.真遺憾，他們竟然忘記了通知你這件事。
i’d rather you came tomorrow.我倒希望你明天來。
if only he were alive.他活著就好了。
it’s (high) time that we went home.我們應該回家。
真題：if only he ____ quietly as the doctor instructed, he would not suffer so much now. (00上海)
a. lies b. lay c. had lain d. should lie
解析：在他“現在”遭罪之前應遵醫囑“靜臥”，但他過去沒有。與過去事實不符，故選c。