Wind is the great maker of waves. There are exceptions, such as the tidal waves, sometimes produces by earthquakes under the sea. But the waves most of us know are produced by winds blowing over the sea.?Now before constructing an imaginary life history of a typical wave, we need to know certain physical things about it. A wave has height, from trough (low point)to crest (high point),and it has length—the distance from this crest to that of the following wave. The period of the wave means the time it takes for succeeding crests to pass a fixed point. None of these things stays the same— for all depend upon the depth of the water and many other matters.?

The water that makes up a wave does not advance with it across the sea. Each drop of water turns around in a little circle with the passing of the wave, but returns very nearly to its original position. And it is fortunate that this is so, for if the huge masses of water that make up a wave actually moved across the sea, sailing would be impossible.

If we want to find the speed of a wave, we may use the following way:

Speeding=Wavelength×Frequency

Here, wavelength is the distance between two high points (crests), frequency means the number of cycles per second.?

41.What causes waves according to the passage??

Earthquakes and nothing else.   B. Wind and volcanos.

C. Wind and earthquakes.          D. Wind and water.

42.Which of the following is true according to the text??

A. The water of a wave moves away across the sea.?

B. The water of a wave remains almost in the same place.?

C. The water of a wave goes with the passing of the wave.?

D. The length of a wave means the distance between crest and trough.

43.The underlined word “succeeding” means__________.?

A. reaching an aim    B. doing well?  C. following after   D. taking place

44.If the speed of wave 1 is 100 cm/s, and its frequency 10;and the frequency of wave 2 is 300,while its speed is twice that of wave 1.Which of the following is true??

A. The wave-lengths of the two are equal.?

B. The wave-length of wave 1 is 10 times longer than that of Wave 2.?

C. The wave-length of wave 2 is longer than that of wave 1.?

D. The wave-length of wave 1 is longer than that of wave 2.?

E

Babies are not just passing idle time when they stare goggle-eyed at the television—they are actually learning about the world, U.S. researchers said. Parents may want t limit what their babies see on television , based on the study, said Donna Mumme, assistant professor of psychology at Tufts University in Boston, who led the research. “Children as young as 12 months are making decisions based n the emotional(情感的)reactions of adults around them,” Mumme said in a statement. “It turns out they can also use emotional information they pick up from television. This means that adults might want to think twice before they speak in a loud and harsh voice or let a baby see television programs meant for information about the world. A mother urging her baby to eat some  “yummy” soup on a brother crying in fear when a dog approaches can influence a baby’s reaction. Mumme’s team tested babies to determine. If television has the same influence, showing actors reacting on a videotape to objects such as red spiral letter holder, a blue humpy ball, and a yellow garden hose attachment. Babies aged 10 months or 12 months were later given the same objects to play with. Ten-month-olds did not seem to e influenced by the video buy the 1-year-olds were. When the actors acted neutrally or positively to an object, the babies happily played with them. But if the actor had seemed afraid or disgusted, the babies would avoid the object.

72.Psychology is the study of              .

       A.human’s society and its growth

       B.human’s hopes had dreams

       C.human’s mind and behaviors

       D.human’s languages and cultures

73.Which of the following is Mumme’s conclusion?

       A.Small babies should not be allowed to watch television programs.

       B.Adults need to think twice before they act in front of small babies.

       C.TV programs provide small babies with all the information they need.

       D.One-year-olds can be emotionally influenced by TV programs.

74.Mumme reached his conclusion by            .

       A.measuring the time babies spent in front of TV.

       B.making TV programs and advertisements for kids.

       C.showing actors how to react to blue bumpy balls

       D.observing small babies’ reactions to TV programs

75.Which of the following may the study lead to according to the researchers?

       A.Parents may want to limit what their babies see on television.

       B.Actors may try to behave themselves well in front of babies.

       C.Babies may be allowed to choose what they see on TV.

       D.Scientists may stop ignoring babies’ emotional world.

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