填空题

If we (know)（）the basic principles, we should have controlled the process even better.

【参考答案】

had known
<上一题 目录 下一题>
热门 试题

填空题
When (heat) （）, ice will be changed into water.
填空题
The pupils will get (confuse)（）if they are made to learn too much.
相关试题