题目内容：

根据句意和汉语注释，写出单词的正确形式。

1.Heart trouble is one of the most serious causes of _________（死）among old people.

2.Hundreds of students pushed to get into a room _________（拥挤的）with photographers and TV cameramen.       

3.The exercise was too difficult. It was _________（超过）the abilities of most of the class.

4.The earth is only a baby _________（比较）with many other celestial bodies（天体）.