典型形式主语考题分析Is __________ necessary to complete the design before National Day? A. this B. that C. it D. he【分析】此题应选C，其余各项均有一定的干扰性。这里主要考查形式主语it的用法。一般说来，当主语是比较复杂的成分(如不定式、动名词、从句等)时，通常在句首使用形式主语 it，而把真正的主语放在后面：Is it necessary to tell his father everything?有必要把这一切都告诉他父亲吗?It is wrong to say anything like that on that occasion. 在那种场合说那样的话是错误的。It’s no good sitting up too late. 熬夜没有好处。It’ll be wonderful lying on the beach all day. 整天躺在海滩上该是多么妙啊!It is quite clear that he has read the book. 很显然，他读过这本书。It’s a problem where we could get so much money. 我们到哪里去弄这么多钱，这是一个难题。有时可在用作主语的不定式前加上介词 for / of短语：It is very kind of you to say that. 你这样说，真是太好了。It is important for us to keep the balance of nature. 我们要保持生态平衡，这点很重要。
