题目

Questioning can lead to  61   (search) for an answer. If we are in the habit of raising doubts as to   62   or not the thing we are told is true, we can find the correct answer and learn more. Two years ago, our teacher   63   (offer) us an answer to a difficult math problem in class. Although the answer seemed a little strange, nobody   64   I doubted it. Thinking that his answer might be wrong, I   65    (careful) analyzed the problem and tried to work   66   out in a different way. Half an hour later, I managed  67   (find) the correct answer. When I sho在开发利用下列资源时要十分注意珍惜和节约使用的是（　　）A．草场资源B．耕地资源C．水资源D．石油资源