He said that he ?[填空] not seen her that day .

The poet has____ fame all his life, but has never experienced it.

Before taking off, they were asked to ____ their seat-belts.

The airplane?[填空] is taking off?is?making a lot of noise.

All things ____, the planned trip will have to be called off.

21.If it ________ tomorrow, the match would be put off.

20. He talks as if he _____the manager here.

The Swedish Academy announces that it will ?not hand out the Nobel Prize in Literature this year in view of the reduced ?public confidence. It ______ to award double prizes next year.

She has breakfast at seven everyday, _____?

Trees mainly serve man in three important ways: They provide him with wood and other products; they provide him shade; and they help to prevent droughts and floods.Unfortunately, in many parts of the world, man has not realized that the third of these services is the most important．In his eagerness to make money from trees, he has cut them down in large numbers, only to find that without them he has lost the best friends he had. And besides, he is usually too careless to plant and look after new trees. So the forests slowly disappear.This does not only mean that man will have fewer trees. The results are even more serious: for where there are trees, their roots break up soil allowing the rain to sink in and also bind(固定) the soil, thus preventing it from being washed away easily；but where there are no trees, the rain falls on hard ground and flows away, causing floods and carrying away the rich top-soil. When the top-soil is gone, nothing remains but worthless desert.Two thousand years ago，a rich and powerful country cut down its trees to build warships, with which to gain itself an empire．It set up the empire, but, without its trees, its soil became poor and grew weak. When the empire fell to pieces, the home country found itself faced by floods and starvation(饥荒)．Why did the country mentioned in the passage suffer from floods and starvations?