盐水泥的强度等级分为()等级
A.32.5、32.5R
B.42.5、42.5R
C.52.5、52.5R
D.62.5、62.5R
E.72.5、72.5R
参考答案:B, C, D
—Why, this is Henry speaking.
—Oh, I’m sorry. I didn’t ________ your voice on the phone.
A.recognize
B.realize
C.know
D.hear
引水隧洞转弯时弯曲半径一般大于5倍洞径,转角( ),以使水流平顺,减少水头损失。
A.不宜小于60° B.不宜大于60°C.不宜小于70° D.不宜大于70°