They are sorry to hear that the famous singer __________ for half an hour.

A. has left　　　B. has gone　　　C. has been away　　　D. has been

This picture ______________ to a museum in New York in 1977.

A. sells　　　B. sold　　　C. is sold　　　D. was sold

－_________ do you have an English party?

－Once a month.

A. How old　　　B. How far　　　C. How long　　　D. How often

－Where can you see the notice“ALL CLOTHES HALF-PRICE”?

－__________________.

A. In a bank.　　　B. In a shop.　　　C. In an office.　　　D. In a cinema

How long can you hold your breath _________(在水下)？

Let’s go to the beach to _________(洗澡).

How does sea water s_________ clean?

The oceans of the world are s_________ because they contain 3.5% of salt.

Coral is not a plant but a _________(各种各样)of animal life of different shapes and bright colors.

Water is lost because of the _________(热)of the sun.