Complete the dialogue with proper words or sentences.

A:Hello.May I小题1:     Mr Brown?

B:Sorry,he isn’ t in .He小题2:     to France.

A:Well,then do you know小题3:     ?

B:He said he could return in a month.

A:Oh,such a long time .小题4:     can I get in touch with him?

B:You may小题5:     .

A;What’s his telephone number ?

B:It’s 00344760488523.

预混合型燃烧器的层流火焰通常可大致分为（）个区域，其中（）区是原子吸收的主要观测区。