在同一截面绑扎接头受力钢筋面积占受力钢筋总面积受拉区的比率不应大于______。
A.20%
B.25%
C.30%
D.50%
参考答案:B
同意句转化。
1. Lingling is my name.
My _____ Lingling.
2. I'm twelve years old.
I ______ _____.
3. Beijing is his hometown (家乡).
He _____ ______ Beijing.
4. I'm OK
I'm ______.
I'm very .
5. Daming is a Chinese boy.
Daming is ______ .
孕甾-4-烯-3,20-二酮的结构式是()。
A.A
B.B
C.C
D.D
E.E