高等教育 / 大学英语(一)
(单选题) When metal is heated and then quickly cooled, _ _ _ _ _ _ _ _ , by dipping in water, it becomes very hard.
A、in general
B、for example
C、on the other hand
D、what's more
A、in general
B、for example
C、on the other hand
D、what's more
参考答案：
佳题速递：