弯曲变形的产生是由于焊缝（）引起的。
A、横向收缩
B、扭曲
C、纵向收缩
参考答案：C
_________in the regulation that you should not tell other people the password of your e-mail account. [ ]
A. What is required
B. What requires
C. It is required
D. It requires
_______ bananas do you need?[ ]
A. How
B. How many
C. How much
D. What
