对情节严重的异常交易行为，证券交易所不得采取的措施是（）。 A.口头或书面警告 B.

—Excuse me, will the plane for Beijing          within an hour?

—I’m not sure. You can go to the Information Desk for help.

A．get off

B．take off

C．turn off

D．show off

---Where did you find the professor who made the speech yesterday?

--- It was in the hall ____ the students often have a meeting.

A．Where

B．which

C．that

D．when

人类早期传递信息的工具有______、______等，现代传递信息的工具有______、______等．

《煤矿安全规程》规定，轨道的接头间隙不得大于（）。

讨论、发现学习、辅导以及协作学习都属于学生主导的教学方法。