钢中氢含量高会使钢产生()缺陷。
参考答案:白点
根据句意和首写字母完成单词。
1. I am glad to r______ your present.
2. Look! what a p______ photo.
3. We are going to c______ this weekend.
4. There are two boys and two girls in the d______.
5. I e______ Beijing during the Olympic Games last year.
开路系统比闭路系统的产量高。