目前抽放瓦斯钻孔直径一般为（）mm。A、40～60 B、60～110 C、110～1

Having a trip abroad is certainly good for the old couple, but it remains _____ whether they will enjoy it. [ ]

A. to see

B. to be seen

C. seeing

D. see

下列不属于Ⅱ类切口的手术是（）。

A.胃大部切除

B.右半结肠切除

C.6小时内伤口清创术

D.甲状腺次全切除

E.胆囊切除术

Mary actually saw lung cancer kill her father，who had smoked ________ since he was a teenager.

[ ]

A．badly  

B．seriously

C．heavily  

D．fiercely

曲轴整体弯曲度超过（）应进行标正。

A、0.1㎜

B、0.2㎜

C、0.3㎜

大型油罐的进出口管线上为什么安装有金属软管？