水泥的代号为P·S。
A.硅酸盐
B.普通硅酸盐
C.矿渣硅酸盐
D.火山灰质硅酸盐
参考答案:C
—We can use QQ to talk with each other on the Internet.
—Really? But can you tell me _______it.
A.how I can use
B.how can I use
C.why can I use
D.when I can use