矿渣硅酸盐水泥具有以F哪种特性()
A．早期强度高，后期强度增进率小
B．抗冻性能好
C．保水性能好
D．水化热低
参考答案：C
下列每句中各有一处错误，请选出来并改正。
( ) 1. What is this on English? _______________
A B C D
( ) 2. I like play football. _______________
( ) 3. What colour is your shoes? _______________
( ) 4. My ball is white and he ball is blue. _______________
( ) 5. Who's that in picture 1? _______________
( ) 6. Is his coat black and blue? It's black. _______________
反馈控制的实质是一个按( )控制的过程。
A．被控量
B．偏差
C．控制器
D．控制量
