【正文】
____from cars is a (13)_________problem.David:You39。re (14)_________right. Carbon dioxide is the gas that does most ( 15)_________to the atmosphere. But we have a problem with trees too. You see, trees give out ( 16 )_________ and ( 17)___________ carbon dioxide. So they39。re very useful because they use up the carbon dioxide.Interviewer:I know what you39。re going to say. We39。re cutting down all the trees.David:Yes, we cut them down because we need the land and because we use the wood for paper and(18)____________. That leaves more carbon dioxide in the atmosphere.Interviewer:It39。s a terrible ( 19 )___________.David:Yes, and another problem is all the ( 20 )______that we produce. We burn a lot of garbage, and once again, the gases pollute the atmosphere. The situation couldn39。t be ( 21 )_______, really.Interviewer:We should (22) ___________garbage, not burn it.David:Of course we should.Interviewer:It39。s strange, we know all this, and yet we do nothing but talk about it. I can39。t help but feel very (23 )__________.David:Yes, well, it is (24 )_________. But governments are beginning to do something about it. I don39。t think it39。s too late.III Grammar: infinitiveEx1.Fill in the blanks with the verbs in their proper forms.1. It39。s very kind of you ________ it for me. (do) job is ________ the students English. (teach) you want ________ with us, you should be ready by eight o39。clock.(go) dare not ________ him about it. (tell) told me ________ at six thirty. (leave) children are warned ________ in that lake. (not swim) you leave the room, please remember ________ the light. (turn off)39。d better ________(stay) at home and ________ (do) your homework.