阅读下面材料，在空白处填入适当的内容（不多于3个单词）或括号内单词的正确形式。
As we all know, questioning can lead to(search) for an answer. If we are in the habit of raising doubts as towhat we are told is true, we can find the correct answer and learn more.
Two years ago, our teacher(offer) us an answer to a difficult math problem in class. Although the answer seemed a little strange, nobody me doubted it. Thinking that his answer might be wrong, I(careful) analyzed the problem and tried to workout in a different way. Half an hour (late), I managed to find the correct answer. When I showed my answer to him, the teacher praised me for my(depend) thinking.
From this experience, I have learned that questioning can serve asbridge that helps us to seek the_(true).