The sign “@” in zhonghua @sina.com means ________ .

A. a.         B.on          C.at           D.in

We often see the sign            in a busy street. So don’t park your car there.

We often see the sign“____”in reading rooms．

　　A．NO FISHING　　B．NO SMOKING　　C．NO PARKING　　D．NO SWIMMINIG．

We often see the sign  in museums. It means _______.

A. NO PHOTOS　　　　　　　　  B. NO FISHING

C. NO SMOKING　　　　　　    D. NO SWIMMING