—What are you going to do this weekend?

      . If time permits, I may go to Shanghai with my friends.

A．Don’t mention it

B．It doesn’t matter

C．Forget it

D．It depends

抢救心跳呼吸骤停的首要步骤是()。

A．确保呼吸道通畅

B．开通静脉通道

C．口对口人工呼吸

D．胸外心脏按压

E．气管插管