( B )The world itself is becoming much smaller by using mode

( B )The world itself is becoming much smaller by using modern traffic and modern communication means.Life today is much easier than it was hundreds of years ago,but it has brought new problems.One of the biggest is pollution.To pollute means to make things dirty.Pollution comes in many ways.We see it,smell it,drink it and even hear it.Man has been polluting the earth.The more people,the more pollution.Many years ago,the problem was not so serious because there were not so many people.When the land was used up or the river was dirty in a place,men moved to another place.But this is no longer true.Man is now slowly polluting the whole world.Air pollution is still the most serious.It’s bad to all living things in the world,but it is not only one kind of pollution.Water pollution kills our fish and pollutes our drinking water.Noise pollution makes us become angry more easily.Many countries are making rules to fight pollution.They stop the people from burning coal in house and factories in the city,and from blowing dirty smoke into the air.The pollution of SO2 is now the most dangerous problem of air pollution.It is caused by heavy traffic.It is sure that if there are fewer people driving,there will be less air pollution.The earth is our home.We must take care of it.That means keeping the land,water and air clean.And we must keep careful of the rise in population at the same time.
66.Our world is becoming much smaller ______.
A.because the earth is being polluted day and night
B.thanks to science developing
C.because of the rise in population
D.because the earth is blown away by the wind every year
67.Thousands of years ago,life was _____it is today.
A.much easier than
B.as easy as
C.as hard as
D.much harder than
68.Pollution comes in many ways.We can even hear it.Here “it” means _____.
A.water pollution
B.air pollution
C.noise polluting
D.rubbish
69.Air pollution is the most serious kind of pollution because _____.
A.it’s bad to all living things in the world
B.it makes us become angry more easily
C.it has made our rivers and lakes dirty
D.it makes much noise
70.Which of the following is not true?
A.The problem of pollution is not so serious because there are not so many people.
B.From now on,maybe people try to go to work by bus or bike instead of car or motorbike.It is helpful to fight against the problem of SO2.
C.The pollution of the earth grows as fast as the world’s population does.
D.Many countries are making rules to fight pollution.