工商行政管理机关行政行为—旦合法成立，就发生一定的法律效力，其不具备的效力是( )。
A．拘束力
B．确定力
C．执行力
D．权威力
参考答案：D
— Do you think it's a good idea to make friends with your students ?
— ______, I do. I think it's a great idea. [ ]
A. Really
B. Obviously
C. Actually
D. Cenerally
当发动机出现什么情况时，必须进行大修？
