Everyone can help to save paper.If we all ___ ,we can help protect trees .

题目

Everyone can help to save paper.If we all ___ ,we can help protect trees .
A think carefully B think over it
C think it about D think careful
最好能指点一下不能选其他项的理由

答案

这道题选A
think既可以当及物动词也可以当不及物动词
看了这个你就知道 C为什么不行了 因为think about是由动词和介词组成
宾语只能放在其后
因为think carefully是考虑再三的意思所以选A