Question

chatting online can be _fun,but kids must be sure they stay

Answer 1

chatting online can be _fun,but kids must be sure they stay safe on_web

A./ ;a B.a;the C./;the D.a;a

选C.

be fun很有趣,常用短语,不含冠词.

web表示“网页”经常加定冠词或形容词性物主代词、所有格.如：

So we have meetings--big meetings -on【 the web 】for disclosure of important information.

因此有大型的网络会议,用于在网上宣布重要信息

但注意：“一个网址”：a web site.