Suspecting the traveler of carrying drugs，the Customs official stopped him and________his suitcase，

but found nothing at all.[      ]

A．looked up

B．went through

C．searched for 

 D．referred to

Netscape公司的Communicator软件属于( )。

A．演示出版软件

B．桌面应用软件

C．浏览工具软件

D．电子邮件软件