If you really have to leave during the meeting, you’d better leave ____ the back door.    

A．for

B．by

C．across

D．out

目前，在烟青虫预测预报调查中，其调查内容主要包括（）等

A、诱集成虫

B、田间查蛹

C、田间查卵

D、田间查幼虫