拉深时，坯料变形区在切向压应力和径向拉应力的作用下，产生切向伸长和径向压缩的变形。
参考答案：错
–What did the radio say just now?
- Sorry. I didn’t catch it. I _____ something else.
A．think
B．will think
C．was thinking
D．had thought
