A.2min15s+20s B.3min15s+20s C.5min45s+20s D.1min15s+20s
A.皮碗磨耗 B.活塞裂纹 C.皮碗直径小 D.活塞杆弯曲
A.不得 B.可以 C.应该 D.尽量