公称直径为4mm的乙级冷拨低碳钢丝拉伸试验的伸长率指标为（）。
A.≥3.0%
B.≥2.5%
C.≥2.0%
D.≥1.5%
参考答案：C
阅读短文，然后判断正“T”误“F”。
I have two friends. This is Sarah. She is a girl. She lives in Canada. She is 8. She is my friend. And this is
Wu Yifan. He is a boy. He is 9. He lives in China. He is my friend, too.
( ) 1. I have three friends.
( ) 2. Sarah is eight.
( ) 3. Wu Yifan is a boy.
( ) 4. Sarah lives in China.
( ) 5. Wu Yifan is ten.
裂纹及焊缝开裂时须清除裂纹，按规定开坡口焊修。
