比如 To develop more accurate population forecasts, demographers would have to know a great deal more than(they do) now about the social and economic determinants of fertility. 如果没有补出they do,就变成了a great deal和now的比较,比较对象不对等
than没说后面不能加句子吧??本身的词性是conj. Only seven people this century have been killed by the great white shark, 这题一个问题是the ones不能指人,曼哈顿上解释去其实我也没看懂,我只能理解这题是一句话和一句话的对比,如果仅仅是人和人的对比,他应该是only seven people, fewer than those blablabla, have been killed by blablabla。否则我也可以理解成是only seven people this century have been killed by shark, fewer than the people has been killed by those have been killed by bee stings???还是一种状态的比较吧