TB/T2658.21—2007标准规定，用单探头探测焊缝轨底时，仪器测距不应大于横波声程25mm。
参考答案：错
词语运用。
1. My _________ (爱好) are reading, singing and dancing.
2. The glasses he _________ (戴) a moment ago are broken. He needs a new pair.
3. Mrs. Smith smiled _________ (幸福) when she received a present from her son on Mother's Day.
4. Alice is so nice that everyone likes to _________ (交朋友).
5. Don't be afraid of making mistakes in class. You won't be ________ (嘲笑).
普通钢筋混凝土电杆，当电杆直径300mm时，其最小配筋量应为（）。
A.mm；
B.mm；
C.mm；
D.mm。
300mm时，其最小配筋量应为（）。
mm；
mm；
mm；
mm。