动态偏差面积是衡量电气传动控制系统最重要的动态性能指标之一。( )
参考答案:对
Fred and Jim did not like each other at first,but ______ they became friends. [ ]
A. in time
B. on time
C. in turn
D. by turns
I like fruit, ______ Tom doesn’t.[ ]
A. and
B. but
C. or
D. do