________ the Internet is bridging the distance between people, it may also be breaking some homes or will cause other family problems.

A．When

B．While

C．If

D．As

食物中毒调查中，下列调查内容是必须的。

进行食物中毒调查时，膳食调查有关数字资料有哪些（）。

A.48小时膳调

B.72小时膳调

C.24小时膳调

D.12小时膳调

E.36小时膳调

F.96小时膳调