同义句转换

1. The soldiers kept working day and night so that they could save more people's lives.

    The soldiers kept working day and night ______ ______ ______ ______ more people's lives.

2. To read English aloud every morning is very necessary.

    ______ ______ necessary ______ ______ English aloud every morning.  

3. These questions are very easy. We can understand them.

    These questions are not _____ for us _____ ______.

4. The next place that we'll visit is the famous Slender West Lake.

    The next place ______ us ______ _______ is the famous Slender West Lake.

一般发动机活塞裙部尺寸加工成（）。

A.圆形

B.椭圆形

C.锥形

D.波浪形