1、目前国家正在提倡建设节约型社会。请你结合生活实际，以How to build an economized mized society为题为某中学生英语报写一篇短文。词数120-150之间。

21、It gives a general introduction to computers!           , the cause also provides practical experience.

A. in addition          B. that is to say          C. in a word           D. to the point

20、Before you put forward an argument, you should collect facts ________ your viewpoint.

A. which to base on                       B. with which to support

C. with which to base                       D. which to support on

19、Shining down out of a blue sky, ________.

A. they were burnt by the fierce sun              B. the sun burnt their pale skins

C. their pale skins were burnt by the son             D. and the sun burnt their cheeks fiercely

18、--Do you know any result about the operation?

--No. what we only know is that the doctors________ it the whole morning.

A. carried out                              B. have carried out

C. were carrying out                              D. have been carrying out

17、It is a good plan in theory, but it ________ to be seen if it works in practice.

A. remains           B. stays             C. stands            D. waits

16、--There must be a dozen pens in this house but I can never find one when I need one.

--Keep looking. ________ is sure to turn up.                     

A. One               B. It                  C. That               D. This