阅读下面短文，从短文后各题所给的四个选项（A, B, C和D）中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。
In 2000 a report was published about what the earth might be like 20 years from then on. The report was a result of a three-year         .
According to the report, the picture of the earth in the year 2020 is not a         one. The world will be more _       _ because the population will continue to grow. The population could be_       6 900 million, almost 2 450 million more than in 1995. More people would move into cities, especially cities in _       _ countries. Cities like Cairo and Jakarta probably would_       have 15 million by then.
Food production will _       , but not enough to feed all the people. Farmers will grow 90% more food than they did in 1995, _       most of the increase would be in countries that _       produce enough food for their people. Little increase is         in South Asia, Africa and the Middle East. Poor farming ways are         large areas of crop land, changing farms into deserts. More farmland is         as cities become larger and more houses are built.        will get worse as industrial countries burn more coal and oil. Many of the world’s _       _  could disappear as more and more trees are cut down. Energy will continue to be a serious problem. The experts say their picture of the earth for the year 2020         . But they only carried out the situation that_       today. By changing the situation, by_       the problems, the picture can be changed. There is        _time for the nations of the world to work         a plan of action. But they warned that_       too long making decisions would greatly reduce the chances of success.

A．learning B．project C．notice D．study

A．pleased B．pleasant C．safe D．blue

A．dangerous B．beautiful C．crowded D．terrible

A．no more than B．as many as C．as much as D．as large as

A．developing B．developed C．big D．mountainous

A．none B．each C．all D．neither

A．insist B．reduce C．increase D．continue

A．so B．but C．or D．however

A．already B．hardly C．partly D．never

A．wanted B．lacked C．found D．known

A．destroying B．protecting C．disturbing D．interrupting

A．saved B．lost C．discovered D．found

A．Air pollution B．Water pollution C．Some diseases D．All farmland

A．animals B．plants C．forests D．people

A．must be true B．will come true C．can't be true D．may be wrong

A．happens B．develops C．exists D．makes

A．settling B．working C．answering D．dealing

A．no B．still C．less D．plenty of

A．about B．in C．out D．for

A．working B．suggesting C．spending D．waiting