This is a dangerous world we live in. The number of murders goes up every year,
people are dying of cancer, more people contract (感染)HIV, more teens are using
drugs, etc. You know this because you"ve heard all the statistics on the news and in
the paper. But do you really have an accurate idea what they mean? The numbers
are going up, but how do they compare to the growth in population? Are more cases
of these diseases being reported because of better testing techniques, or are the
diseases more common? The fact is that without knowing the background statistics
mean very little.
This growing trend of reporting only part of the information is becoming dangerous.
For example, several years ago a high school student reported the dangers of the
chemical known as dihydrogen monoxide. This chemical,found in most cancerous
umors(肿瘤 ) ,is often found in the blood of people drunk on alcohol, and causes
complete physical and mental dependence for those who take the chemical even once.
After reading his report, more than 75% of his Advanced Placement Chemistry class
voted to forbid this dangerous chemical! Every one of the above statements is true,
yet this chemical is necessary to all life on earth. The students made the mistake
because they voted knowing only a few statements and statistics, rather than the
chemical"s full background.
The point of this article is that one should be aware of what is and is not being
said. When one finds a new fact or number , one should try to consider other
important information before forming an opinion with only half-truths. Always
remember that the author is trying to convince you of his or her own view, and
will leave out information that is different to his view. For example, look again at
the statistics that suggest skiing is safe. Only 32 people may die each year when
skiing, while 897 die from lightning strikes, but which is really the most dangerous?
If you think about it, you realize far fewer people go skiing each year than the number
of people who are in danger of a lightening strike. When you think about it ,skiing
is more dangerous than you might at first think when looking at statistics. lf we
teenagers are to be left this world. we had better be able to think critically, and
form our own views, rather than be easily persuaded by another"s. To be warned
is to be prepared.
Polar bears live in the coldest environments on Earth-the Arctic. Called "ice bears" in many
European languages, polar bears depend on the ice that surrounds them for their survival. As the
Arctic climate changes and the ice slowly disappears, polar bears face an increasingly uncertain
future.
Polar bears impress us with their incredible size, power and ability to survive in the cold Arctic.
These giants can stand three meters tall and weigh over 500kg, and they spend their lives traveling
throughout the Arctic. Two layers of fur keep them warm. Interestingly,the hairs are hollow in order
to direct the sunlight straight to the skin. Undemeath their fur, polar bears have an
additional l0-cm-layer of fat.
Polar bears hunt ringed seals (环斑海豹), which live under the Arctic ice. They wait patiently
for hours beside holes in the ice pack (浮冰群) for seals to surface and breathe. Using their great
strength , the bears pull the heavy animals up onto the ice. The seals provide much of the fat the
bears need for warmth.
Since 2006 , polar bears have been labeled a vulnerable (脆弱的) species. Most experts feel
the threat to polar bears comes not from hunters or predators(食肉动物),but from the gradual melting
of Arctic ice. Due to global climate change, the Arctic region is getting warmer. Arctic ice is breaking
up earlier in the spring, and its area is decreasing.
Problems polar bears around Canada"s Hudson Bay are facing may indicate what lies ahead for
polar bears elsewhere. Hudson Bay is located at the southern limit of the polar bears" territory(领地) .
Currently,the ice there breaks up three weeks earlier in the spring than it did 20 years ago. Polar
bears on Hudson Bay fast during the summer,waiting for ice to form in the fall to hunt. Every year,the
Summer gets longer, and the bears get skinner. Over the past 25 years, the average weight of the
female bears has dropped 68kg. This loss affects their ability to reproduce, and already the number
of births has dropped 15% . Unless the bears can leam to survive global climate change, the giants
of the ice may one day disappear.
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