2013年以来,原央视著名主持人崔永元和科普作家方舟子就转基因食品的安全问题进行了激烈的论战,引起了很多人对转基因食品的关注.以下关于基因的说法,正确的是( ) A . 基因位于DNA上,一个DNA分子上有一个基因 B . 利用基因的多样性可以培育很多农作物新品种 C . 每一种生物都是一个基因库,它们的基因都是相同的 D . 如果由于外部因素导致基因改变,这一改变的基因就会遗传给后代Do you think there is too much noise in our city? If
you live near an airport,you will be unhappy because of a plane
often make a loud noise.The sound of planes or heavy vehicles is
likely to cause deafness if heard continuously(不断地).
However, most people in our city do not seem to mind
noise. They like to enjoy music when they are doing uninteresting jobs.It is a new danger because pop music,when played through powerful amplifiers(放大器),can reach 120 decibels(120分贝的)at a distance of five feet.A continuous noise of over 85 decibels can cause
deafness.It was discovered that many young people in
America could hear no better than 65-year-old people.
In the past we used to think that only workers in very
noisy places would become deaf.For example,when newspapers and books are being printed,the noise level is over 85 decibels,and some of the workers become deaf.Today,however,scientists believe that 10 percent of the workers in
Britain are being deafened by the noise.
Sometimes noise of less than 85 decibels can make some
people tired and stressed.We all know that too much noise makes life
difficult and unpleasant.It can do great harm to people's health and
prevent people from working well.Workers in
noisy offices are not as efficient(效率高的)as those
in quiet offices.Noise makes people less efficient.Can anything be done to reduce or control noise?
In Britain the government has made several laws to
reduce noise.Though
the government has spent a lot of money in making airports and main roads
quieter,many people think that there are still not
enough laws.For example,there
are no laws to control the noise of machines.In Japan,America and Norway there are such laws.As a result,workers can
be given compensation(赔偿)if they become deaf.
1.Some workers become deaf
because of ________.
A.hard
work
B.a continuous noise of over 85 decibels
C. powerful amplifiers D.uninteresting jobs
2.In Britain there are laws to ________.
A.stop workers from
becoming deaf B.control the noise of machines
C.keep down
noise
D.help deaf workers in need
3.Who can be given compensation if they become deaf?
A.American workers.
B.British workers.
C.Both American workers and
British workers.
D.None of the above answers.