变幅机构是用来改变起重机幅度的机构。
参考答案：对
His careless driving ___ him his life last year.
A．spent
B．paid
C．took
D．cost.
星状神经节阻滞后出现的症状中，哪个是错的（）
A.瞳孔缩小
B.眼睑下垂
C.眼球凹陷
D.球结膜充血
E.出汗
