We would like to our English teacher. [ ]
A. talk
B. to talk
C. talking
D. will talk
答案:B
克劳斯催化剂还原操作反应方程式系数正确的是Al2(SO4)3+H2S→Al2O3+()SO3+H2O。()。
A、1
B、2
C、3
D、4
电机空载试车时间一般要求在2个小时左右。()