The computer mouse derives its name from the cable that goes out its b

According to the author, general computer users need not know how the computer mouse was invented.（）

A

True

B

False

C

Not Given

People began to rely on the mouse for routine computer tasks ever since Stanford University invented computer mouse.（）

A

True

B

False

C

Not Given

Among all the computer pointing devices, touch screen is the most expensive one.（）

A

True

B

False

C

Not Given

材料全屏

Computer Mouse

【*】The basic computer mouse is an amazingly clever invention with a relatively simple design that allows us to point at things on the computer and it is very productive. Think of all the things you can do with a mouse like selecting text for copying and pasting, drawing, and even scrolling on the page with the newer mice with the wheel. Most of us use the computer mouse daily without stopping to think how it works until it gets dirty and we have to learn how to clean it. We learn to point at thing before we learn to speak, so the mouse is a very natural pointing device. Other computer pointing devices include light pens, graphics tablets and touch screen, but the mouse still our workhorse.

【*】The computer mouse was invented in 1964 by Douglas Englehart of Stanford University. As computer screens became popular and arrow keys were used to move around a body of text, it became clear that a pointing device that allowed easier motion through the text and even selection of text would be very useful. The introduction of the mouse, with the Apple Lisa computer in 1983, really started the computer public on the road to relying on the mouse for routine computer tasks.

【*】How does the mouse work? We have to start at the bottom, so think upside down for now. It all starts with mouse ball. As the mouse ball in the bottom of the mouse rolls over the mouse pad, it presses against and turns two shafts. The shafts are connected to wheels with several small holes in them. The wheels have a pair of small electronic light-emitting devices called light emitting diodes (LED)mounted on either side. One LED sends a light beam to the LED on the other side. As the wheels spin and a hole rotates by, the light beam get through to the LED on the other side. But a moment later the light beam is blocked until the next hole is in place. The LED detects a changing pattern of light, converts the pattern into an electronic signal, and sends the signal to the computer through wires in a cable that goes out the mouse body. This cable is the tail that helps give the mouse its name. The computer interprets the signal to tell it where to position the cursor on the computer screen.

【*】So far we have only discussed the basic computer mouse that most of you probably have or have used. One problem with this design is that the mouse gets dirty as the ball rolls over the surface and picks up the dirt. Eventually you have to clean your mouse. The newer optical mice avoid this problem by having no moving parts.

1

【单选】

Most computer users want to know how the computer mouse works.（）

A

True

B

False

C

Not Given

The Disappearing Honeybee

Do you run away when you hear a bee buzzing? Many people do. A bee sting hurts and some people are allergic to bee venom(蜂毒). But did you know that bees are very important to humans? Honeybees do more than just make honey. They fly around and pollinate(传授花粉) flowers, plants, and trees. ___11___ One third of America's food supply is pollinated by the honeybee.

Have you seen or heard a honeybee lately? Bees are mysteriously disappearing in many parts of the world. Most people don't know about this problem. It is called Colony Collapse Disorder(CCD). Some North American beekeepers lost 80% of their hives(蜂巢)from 2006-2008.___12___.

The disappearance of the honeybee is a serious problem. Can you imagine never eating another blueberry? What about almonds and cherries? Without honeybees food prices will skyrocket(猛涨).___13___.

This problem affects other foods besides fresh produce. Imagine losing your favorite ice cream! Haagen Daaz is a famous ice cream company. Many of their flavors rely on the hard working honey bee. ___14___ They also created a website called helpthehoneybee.com.

Donating money to research is the most important thing humans can do to save the honeybees. Scientists need money to investigate the causes of Colony Collapse Disorder. Some scientists blame CCD on climate change. Others think pesticides(杀虫剂)are killing the bees.___15___Beekeepers transport their hives from place to place in order to pollinate plants year round.

Not everyone has money to donate regularly. There are other ways to help the honeybee. Spread the word, by telling your friends and family about the problem. Tell your teacher about the disappearing bees too. Maybe your class can write a letter to the government.

A. In 2008 Haagen Daaz began raising money for CCD

B. It is hard to pin down what has been causing honeybees to vanish

C. The poorest people always suffer the worst when there is a lack of food

D. Our fruits, nuts, and vegetables rely on these pollinators.

E. Commercial bee migration may also cause CCD.

F. Bees in Italy and Australia are disappearing too.