离合器主动件之一飞轮的检查：主要是与（）接触表面磨损情况的检查。
A、主动盘
B、从动盘
C、离合器盖
D、飞轮接盘
参考答案：B
酶促反应中决定酶特异性的是
A．作用物的类别
B．酶蛋白
C．辅基或辅酶
D．催化基团
E．金属离子
After I ______ my homework, I went out to an aquarium. [ ]
A. was doing
B. did
C. does
D. would do
