The population problem may be the 1 one of the world today． The world's population is growing 2 ． Two thousand years ago, there were only 250 million people 3 the earth． Four hundred years ago, the number was 4 500 million． But at the beginning of the 5 century, the world's population was about 1,700 million．In 1970, this number was 3,600 million． In 1990, the number was five billion． A 6 report says that the world population will 7 six billion by the end of the 20th century． This is just ten 8 after it 9 five billion． People say that by the year 2010, 10 may be seven billion．
1．A．great B．greater C．greatest D．greating
2．A．faster and faster B．fast and fast
C．fastest and fastest D．faster and fast
3．A．in B．on C．at D．for
4．A．nearly B．more C．almost D．over
5．A．twenty B．twelve C．twentieth D．twelfth
6．A．USA B．UN C．PRC D．PLA
7．A．past B．pass C．passed D．passes
8．A．weeks B．months C．seasons D．years
9．A．get B．gets C．reached D．reach
10．A．this B．its C．one D．it
KEY: 1．C 2．A 3．B 4．D 5．C 6．B 7．B 8．D 9．C 10．D
