大学英语四作业 完形填空

题目

大学英语四作业 完形填空
Many of the world's pollution problems have been caused by the crowding of large groups of people into cities.Satisfying the 21 of the people leads to further polluting by industry.If the rapid increase in human population 22 at the present rate (比率),there may be much greater harm.Some scientists speak of the 23 in number of people as "Population Pollution".
About 2000 years ago,the world 24 was probably about 250 million.It reached a billion in 1850.By 1930 the population was two billion.It is 25 three and a half billion.It is 　expected to double by the year 2000.If the population continues to grow at the same 26 ,there would be 25 billion people in the world a hundred years from now.
Man has been using the earth's 27 more and more rapidly over the years.Some of them are almost gone.Now many people believe that man's greatest 28 is how to control the growth of this population.The materials in the world will not support the human population in time to come if the present rate of increase continues.29 there is over crowding in the cities and hunger in some countries.Can man's rate of increase continue?
Many people believe that human survival (幸存者) in the future 30 on the answer to the question.
21
needs
supplies
service
supports
22
stops
continues
slows down
adds to
23
increase
reduce
country
improvement
24
people
situation
population
land
25
now
in the past
in the future
then
26
place
time
rate
result
27
oal
oil
mines
resources
28
problem
power
plan
idea
29
Already
Yet
Still
Often
30
feeds
lives
keeps
depends

答案

21 needs
22 continues
23 increase
24 population
25 then
26 rate
27 resourses
28 problem
29 already
30 depends