硅酸盐水泥的适用范围是( )。
A．受海水浸蚀的工程
B．受化学浸蚀的工程
C．需快硬早强的工程
D．大体积混凝土工程
参考答案：C
Fully ____________ looking after three children at home, she no longer has time to enjoy the various activities in the club.
A．attached
B．occupied
C．contributed
D．devoted
一台目镜是12×，物镜是40×的显微镜，放大倍数是[ ]
A．42
B．50
C．240
D．480
