蝇类的蛹属（）。
A.裸蛹
B.被蛹
C.围蛹
参考答案：C
After a long vacation, Mike came back _________.
A．freshly and strongly
B．fresh and strong
C．being fresh and strong
D．to be fresh and strong
静环的夹紧方式有（）种形式。
A.2
B.1
C.3
D.5
