这道题,作为应试题目可以用各种方法推出正确答案,但是如果是自由填空,则值得仔细推敲。这和指示代词再次被提到关系不大,这里是替代问题。个人认为,因为是简单的动词替代,动作明确,所以使用 do it 是没问题的,但是,使用do that /this 也未尝不可(this据统计出现最少,所以很多书上只提及do it/that/so)。甚至什么都不填亦可,例如:We can also use do alone rather than do so in less formal English, especially after modals or perfect tenses :
• 'Will this programme work on your computer?' 'It should do.'
• I told you that I'd finish the work by today, and I have ('have' is stressed here)
do it 往往替代一个非常明确的动作或事件,do this/ that 意义模糊一些,但是多些感情色彩,有喜欢或讨厌的含义。 do so 则是意义最为模糊的情况。
个人观点,仅供参考。
英语里面,通常当第2次提到的时候,用it,不用this, that
例如:
- What's this? - It's a cat. (回答相当于是第2次提到,不说This is a cat.)
- What's that? - It's a cat. (回答相当于是第2次提到,不说That is a cat.)
类似的,如果是复数,当第2次提到时,用they, 不用these, those.
例如:
- What are these? - They're pears. (回答不说These are pears.)
- What are those? - They're pears. (回答不说Those are pears.)
第6空的代词,代替的是flying kites, 也是第2次提到,用it更好。