A.howB.whyC.whenD.where

A.and

B.but

C.so

D.yet

When wood is burnt, it heat and light, together with heavy smoke.

A.give up

B.sends up

C.sends away

D.sends out

As the journey was a long one, he took a friend with him for ________.

A.pleasure

B.entertainment

C.company

D.defence

A.surprised

B.pleased

C.refused

D.increased

There wouldnt be enough water for us if we didnt _________.

A.turn to the oceans for more water

B.reuse used water and make use of seawater

C.desalt seawater

D.take steps to reuse all water on earth

tes for the last ten years. Computers used to be large, expensive machines that were very difficult to use. But scientists and technicians have been making them smaller and cheaper while at the same time they have been made easier to use. As a result, their popularity has been increasing as more people have been buying computers for their homes and businesses. Computers have been designed to store information and compute problems that are difficult for human beings to work out. Some have voices that speak with the operators. Stores use computers to keep records of their inventories (库存货物) and to send bills to their customers. Offices use computers to copy letters, record business and keep in touch with other offices. People have been using computers in their homes to keep track of the money they spend. One important new use for computers is for entertainment. Many new games have been designed to be played on the computers. People of all ages have been playing these games. People also have been buying home computers to play computer games, watch movies and listen to concerts at home. They have become very popular indeed. Computers used to _______.

A.work rapidly

B.be large and expensive

C.be easy to use

D.be used for fun

A.result from

B.make

C.take

D.result in

It is important us the balance of nature.

A.for…to keep

B.of…to keep

C.for…keeping

D.of…to have kept

Which is ______ country, the United States or Canada?

A.a larger

B.larger

C.the larger

D.the largest

A.where

B.what

C.whose

D.white