客运营业站的启用、封闭和变更时,由所属铁路局(含集团公司)于实施前()天报国务院铁路主管部门审批。
A.50
B.40
C.30
D.60
参考答案:D
________ there a post office and some supermarkets near here?[ ]
A. Have
B. Do
C. Are
D. Is
托辊脱落卷入皮带尾部滚筒极易造成皮带撕裂拉断。