简单说就是： The economic situation is as serious as it was expected to be. 这句话怎么省略？我觉得： 1.只省略to be是不对的（解释见Quirk名著P1131）： The economic situation is as serious as it was expected.（错误） 2.省略it和to be，可以但比较少见，不自然： The economic situation is as serious as was expected. 3. 省略it was和to be，这样最好，也符合惯用法： The economic situation is as serious as expected. 补充一点：与as不同的是，than的类似结构却可以自由使用： It is very possible that the recession will be longer, deeper, and more painful than was expected only a few weeks ago. It is less effective or exciting than was expected or intended. The numbers were smaller than expected. The response has been better than expected.