型钢按断面形状可分为简单断面、复杂断面和()三种。
参考答案:周期断面
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.
货物运输作业由托运人()开始。
A.付费
B.移交货物
C.填写托运单
D.电话洽约承运人