句型转换。

l.John takes photos on Friday.（用now改为现在进行时）

  John                                  now.

2. We enjoy the school trip on Sunday.（同上）

  We                      the school trip now.

3．He is visiting his friends.（对画线部分提问）

                         he                 ?

4．Betty buys her friend a pen.（改为同义句）

  Betty           a pen          her friend.

5．They're enjoying school trip．（改为一般疑问句并作否定回答）

                              enjoying school trip?

  No，                            ．

密闭回路麻醉要满足的一个重要参数是

A．每分通气量
B．潮气量
C．呼吸频率
D．氧耗
E．需要的麻醉药量