在急倾斜突出煤层中采用双上山掘进时，二个上山之间应开联络巷，联络巷间距不得大于（）。
A、5m
B、10m
C、15m
参考答案：B
— No, I'm afraid he isn't in. This is his secretary speaking. Can I help you?
— _____.[ ]
A. Oh, you will.
B. Oh, that's a pity.
C. I should think so.
D. Well, I look forward to hearing from you.
市场增长率高，但相对市场占有率低，这种业务是( )
A．问号业务 B．明星业务 C．金牛业务 D．瘦狗业务
