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