Fire can help people in many ways.  Fire can heat water, (21)____ your house, give light and cook food. But fire can burn things too. Nobody knows (22)____ people began to use fire. One story from Australia tells about a man a very long time ago. He (23)____ the sun by a rope and brought fire down.

Today people know how to (24)____ a fire with matches. Children sometimes like to play with them. But matches can be very (25)____.

Fire kills people every year. So you must be careful (26)____ matches. You should also learn to (27)____ fires. Fires need oxygen（氧气）. Without oxygen they die. There is (28)____ in the air. Cover a fire with water, sand, or (29)____, with your coat or a blanket. This keeps the air from a fire and kills it.

Be careful with fire, and it will help you. Be careless with fire, and it might (30)____ you.

Do you always understand the directions on a bottle of medicine? Do you know what is meant by "Take only as directed"? Read the following directions and see if you understand them.

"To reduce pain, take two tablets (药片) with water, followed by one tablet every eight hours, as required. For night-time and early morning relief, take two tablets at bedtime. Do not take more than six tablets in twenty-four hours.

   For children six to twelve years old, give half the amount. For children under six years old ,ask for your doctor's advice.

Reduce the amount if you suffer from restlessness or sleeplessness after taking the medicine".

1. How many tablets should a nine-year-old child normally take in 24 hours?

A. Half a tablet           B. One tablet.　                  C. Two tablets   D. Four tablets.

2.What is the advice for one who cannot sleep well after taking the medicine?

A. Stop taking the medicine at bedtime

B. Continue to take the normal amount.

C. Take more than the normal amount.     

D. Take less than the normal amount.

3.This text is most probably taken from a .

A. textbook                 B. newsreel                C. doctor's notebook                   D. bottle of medicine

What will power your house in the future? Nuclear, wind, or solar power? According to scientists at the Massachusetts Institute of Technology (MIT) in the US, it might be leaves –but artificial ones.

  Natural leaves are able to change sunlight and water into energy. It is known as photosynthesis (光合作用). Now researchers have found a way to imitate this seemingly simple process.

  The artificial leaf developed by Daniel Nocera and his colleagues at MIT can be seen as a special silicon chip (硅片) with catalysts (催化剂). Similar to natural leaves, it can split water into hydrogen and oxygen when put into a bucket of water. The hydrogen and oxygen gases are then stored in a fuel cell (电池), which uses those two materials to produce electricity, located either on top of a house or beside the house.

  Though the leaf is only about the shape of a poker card, scientists claimed that it is promising to be an inexpensive source of electricity in developing countries. “One can imagine villages in India and Africa not long from now purchasing an affordable basic power system based on this technology,” said Docera at a conference of the American Chemical Society.

  An artificial leaf is not a new idea. The first artificial leaf was invented in 1997 but was too expensive and unstable for practical use. The new leaf, by contrast, is made of cheap materials, easy to use and highly stable. In laboratory studies, Nocera showed that an artificial leaf prorotype (原型) could operate continuously for at least 45 hours without a drop in activity.

  The wonderful improvements come from Nocera’s recent discovery of several powerful new, inexpensive catalysts. These catalysts make the energy transformation (转换) inside the leaf more efficient with water and sunlight. Right now, the new leaf is about 10 times more efficient at carrying out photosynthesis than a natural one. Besides, the device can run in whatever water is available; that is, it doesn’t need pure water. This is important for some countries that don’t have access to pure water.

  With the goal to “make each home its own power station” and “giving energy to the poor”, scientists believe that the new application could be widely used in developing countries, especially in India and rural China.

1.Which of the following order correctly shows how the artificial leaf is used to produce electricity?

a. artificial leaves split water into hydrogen and oxygen

b. the hydrogen and oxygen gases are stored in a fuel cell

c. the artificial leaves are put in water

d. the fuel cell uses hydrogen and oxygen to produce electricity

A. cbad  B. cabd  C. bcad   D. cadb

2.Which of the following statements about new artificial leaves is TRUE according to the article?

A. They are inexpensive but unstable.

B. They are as efficient at carrying out photosynthesis as natural leaves.

C. They can work only in pure water.

D. They need several catalysts to help them work efficiently.

3.The aim of the scientists at MIT in developing the new artificial leaves is to         .

A. build-up more power stations in the world

B. provide cheaper energy for developing countries

C. offer people in developing countries access to pure water

D. gain a deeper understanding of the photosynthesis process

4.What is the main point of the article?

A. Introduction to the history of artificial leaves.

B. An invention copying photosynthesis.

C. Giving energy to the poor.

D. A mixture of water power and solar energy.

 _______ the fact that three quarters of the earth’s surface is covered with water, we can say that it is a ________ planet.

From school to band practice, the Venturi Eclectic is an Earth-friendly way to get where you want to go. This battery-powered, zero-emission (meaning it doesn't pollute the air) vehicle runs mainly on renewable energy. Solar panels on the Eclectic's roof absorb sun rays when you're driving. On windy days, you can connect a machine to the car's roof that collects energy from the wind while you're parked. The Eclectic's top speed is 28 miles an hour; the battery lasts for 31 miles before it needs to be recharged. Zipping (迅速行进) around the neighborhood has never been better.

Here's an eco-friendly way to tell time: Simply fill the Bedol Water-powered Clock's tank (箱) with water, add some lemon juice, and the clock will display the time without the need for environmentally harmful batteries. There are two sets of metal electrodes(电极) inside the water tank. Water contains ions (离子) that carry negative and positive charges. These ions complete a charge between the electrodes, creating enough energy to power the clock. Just refill the tank every few weeks, and this clock will keep on ticking.

You’re having a blast at your friend’s birthday party. But when it's time to bring out the cake, everyone crowds around, blocking your view. No worries. Throw the Triops into the air, and this clever camera catches the view from above. The Triops can take three pictures at once, each from different angles. You can also record sounds and command the Triops to start shooting (拍摄)whenever it hears that noise. That's one smart camera.

1.According to the passage, the Venturi Eclectic      .

A．is popular with businessmen

B．is suitable for a long trip

C．has only a little gas emission

D．can turn wind into energy

2.What is the common characteristic of the Venturi Eclectic and the Bedol Water-powered Clock?

A．They don't need batteries.

B．They can be powered by water.

C．They are difficult to operate.

D．They are environmentally friendly.

3.The underlined phrase “having a blast” in the last paragraph probably means      .

A．looking at a picture                      B．recording sounds

C．enjoying yourself                       D．blowing out a candle