All too often, a choice that seems sustainable(可持续的)turns out on closer examination to be problematic. Probably the best example is the rush to produce ethanol(乙醇) for fuel from corn. Corn is a renewable resource —you can harvest it and grow more, almost limitlessly. So replacing gas with corn ethanol seems like a great idea.
One might get a bit more energy out of the ethanol than that used to make it, which could still make ethanol more sustainable than gas generally, but that’s not the end of the problem. Using corn to make ethanol means less corn is left to feed animals and people, which drives up the cost of food. That result leads to turning the fallow land –including, in some cases, rain forest in places such as Brazil—into farmland, which in turn gives off lots of carbon dioxide (CO) into the air. Finally, over many years, the energy benefit from burning ethanol would make up for the forest loss. But by then, climate change would have progressed so far thatitmight not help.
You cannot really declare any practice “sustainable” until you have done a complete life-cycle analysis of its environmental(环境的) costs. Even then, technology and public keep developing, and that development can lead to unforeseen and undesired results. The admirable goal of living sustainably requires plenty of thought on an ongoing basis.
1.What might directly cause the loss of the forest according to the text?
A. The growing demand for energy to make ethanol
B. The increasing carbon dioxide in the air
C. The greater need for farmland
D. The big change in weather.
2.The underlined word “it” in the second paragraph refers to “ ”
A. the energy benefit B. the forest loss
C. climate change D. burning ethanol
3.The author thinks that replacing gas with corn ethanol is .
A. impractical B. acceptable C. admirable D. useless
4.What does the author mainly discuss in the text?
A. Technology B. Sustainability
C. Ethanol energy D. Environmental protection
Five weeks ago I had a total hip replacement surgery (髋关节置换手术). In Canada, we have great healthcare system. That means we get our new hips for free.
My hip had been hurting me for years before I went to the doctor. Of course, it was free. She referred me to a surgeon, but the earliest appointment was in 10 months. That is what being free gets you. Ten months later, after some free X-rays, the surgeon told me I needed a surgery, which was about an 18-month wait, for some senior citizens had been on the operation list. Another 18 months! I dragged myself out of the surgeon, s office.
Walking through the hospital, I thought about the situation. As the breadwinner of a large family, I couldn’t wait that long, so I had to get to the front line. I was fully aware of what a Canadian should be like (Canadians are usually considered gentle and caring), but this time I really needed to fight for myself. At that very moment, in the shop window of the hospital, I saw a sign which read, “Volunteers Needed.” Suddenly, an idea occurred to me — I would get the job. Fortunately, they signed me up immediately because the average age of the volunteers at the shop was 75. They were desperate for some young blood.
Every Friday morning, I was at the shop. While seeing the hospital staff, I’d casually ask, “What do you do?” Then I’d tell them, “Well, I’m getting my hip replaced — in 18 months.
It’s going to be so great when the pain stops.” Soon, all the staff got to know me. Naturally, in my next appointment, the surgeon recognized me. Moments later, I had a surgery date just weeks away.
I had to say it was actually my volunteering that got me to the front of the line. And I’m not ashamed of it, for I intend to stick with the volunteering. Also, even when I cheated the system, I did it in a way that benefits society.
1.What can we infer from the second paragraph?
A. She felt rather disappointed.
B. She couldn’t walk because of the pain.
C. She was too scared to have the surgery.
D. She didn’t believe what the surgeon said.
2.Why did the writer decide to be a volunteer?
A. To donate blood to the hospital.
B. To get her new hip free of charge.
C. To receive some tiny gifts from others.
D. To approach the doctor for an early surgery.
3.What did the author think of her cheating?
A. It was a shame. B. It was a pride.
C. It was beneficial. D. It was a fair deal.
4.Which can be the best title for the text?
A. How I Got My New Hip
B. The Doctor Who Saved My Life
C. How to Be a Volunteer in Hospital
D. The Problem of Canada Healthcare System
The wonderful experiment I am going to introduce proves that air is just all around and that it presses down upon us. Air pressure is a wonderful force. When you swim underwater, you can feel water push down your body. The air all around you does the same. However, your body is so used to it that you do not notice this. The pressure is caused by a layer of air called the atmosphere. This layer surrounds the Earth, extending to about five kilometers above the Earth’s surface.
The following experiment is an easy one that you can do at home. But make sure that you are supervised, because you will need to use matches. Now for the experiment！
What you need:
·A hard-boiled egg without the shell
·A bottle with a neck slightly smaller than the egg
·A piece of paper
·A match
Method:
1） Check that the paper will sit firmly on the neck of the bottle.
2） Tear the paper into strips and put the strips into the bottle.
3） Light the paper by dropping a burning match into the bottle.
4）Quickly sit the egg on the neck of the bottle.
Result:
Astonishingly, the egg will be sucked into the bottle. Your friends will be amazed when you show them the experiment. But be careful when you handle matches.
Why it happened
As the paper burns, it needs oxygen and uses up the oxygen（air）in the bottle. The egg acts as a seal in the neck of the bottle, so no more air can get inside. This reduces the air pressure inside the bottle. The air pressure must equalize, so more air from outside must enter the bottle. The outside air pressure against the egg and then the egg is pushed into the bottle! This proves that air is all around and that it is pressing down on it.
1.Why is there the need to take care when you are doing the experiment?
A. The bottle could break.
B. You need to light the paper with a match.
C. The egg needs to be shelled.
D. The egg has to be perfectly placed on the neck of the bottle.
2.In the experiment, the burning inside the bottle can ________.
A. equalize the air pressure inside and outside
B. make a seal in the neck of the bottle
C. finish up the oxygen inside the bottle
D. produce more oxygen inside the bottle
3.How was the egg put into the bottle?
A. The oxygen inside the bottle sucked the egg in.
B. It became salt without the shell.
C. The neck of the bottle was wide enough.
D. The outside air pressure forced it into the bottle.
听下面一段较长对话，回答以下小题。
1.How does Steven describe his music?
A. It's hard rock. B. It's folk music. C. It's modern pop.
2.Why does Steven love Australian audiences？
A. They never throw things at him.
B. They buy more of his records.
C. They are more friendly.
3.What's Steven's attitude towards people downloading his music？
A. He doesn't mind. B. He feels upset. C. He is puzzled.
4.What advice does Steven give to songwriters？
A. Listen to more music. B. Stick to their own style. C. Make use of the Internet.
听下面一段较长对话，回答以下小题。
1.Where are the speakers?
A. In a bank. B. On a lake. C. At a hotel.
2.Why does David's father want to spend Christmas in the countryside?
A. He can enjoy the lake view.
B. He can be freed from housework.
C. He can have some peace and quiet.
3.Why is David unhappy?
A. He can't attend the party.
B. He isn't allowed to skate.
C. He has to cook for his parents.
听下面一段较长对话，回答以下小题。
1.How did the man come to the place?
A. By car. B. On foot. C. By train.
2.Why is the man here？
A. To have an interview.
B. To discuss traffic problems.
C. To share his work experience.
