题目内容
Mobile phones have proved to ______ with flight instruments and have a negative effect on
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______ is often the case with a new idea, much initial activity and optimistic discussion
Venus, one of the four inner planets of our solar system, is the closest body in the sky apart from the Moon, sometimes coming only 40 million km from the Earth. Thus, in the not- so-distant future, when man has colonized the Moon, he will start looking at Venus as his next step into space.
As it is now, Venus's environment is totally unfavourable to human life. Its surface temperature is almost 480℃. Its face is almost completely hidden from view by poisonous clouds of 90% carbon dioxide.
But scientists have a simple plan which, they predict, could make Venus habitable.
With the help of rockets, they plan to bombard the carbon dioxide clouds with colonies of blue-green algae. Experiments carried out on Earth have proved that blue-green algae can survive and reproduce normally in such an environment. The algae will consume the carbon and liberate the oxygen. They reproduce so quickly that the carbon dioxide could be broken down within one year. After that, the surface of Venus will be partly visible to telescopes on Earth.
The increase in oxygen will have spectacular effects on the desert planet. As oxygen re- places the carbon dioxide, the sun's infra-red radiation, which up to that moment was trapped under the clouds of carbon dioxide, will escape into space and the temperature of the lower atmosphere will decrease. Soon, water will collect from the atmospheric vapor and rain will start falling for the first time. That first rain will never reach the surface. It will vaporize into steam high up in he Venusian atmosphere, but it will have a very important effect. It will lower the ground temperature, perhaps by 35℃. Soon the rain will fall again and again, until the ground temperature is about 70℃. Then the "Big Rain" will strike the soil of Venus for the first time and the clouds will partly clear away, leaving an oxygen-rich atmosphere and a temperature cool enough to sustain hardy plants and animals from Earth.
According to the passage, which of the following statements is true？
With the example of her great-grandmother, the writer ______ psychologists' definition of
Americans participated in a great debate throughout the 1960s and 1970s. The debate continues into the 1980s and 1990s. It is the argument over whether the use of the 150 million handguns, shotguns, and rifles in the United States should be restricted or banned altogether. And if so, how？
Opinions on what should be done conflict sharply. Many Americans are confused by all that has been said.
On the one hand, we hear that something must be done immediately to stop the havoc wrought by the gun. Statistics tell us that it is responsible for more than 30,000 murders, suicides, and accidental deaths each year. It is used in countless crimes and is said to either breed or reflect the violence that has become such a significant and frightening aspect of our national life.
More than 20,000 Americans are murdered each year. Guns of all types--dries, shotguns, and handguns--are responsible for approximately 66 percent of these deaths. By itself, the handgun is responsible for more than 10,000 deaths.
With an increasing number of lives being taken each year, there is a call to control the gun, to curtail its use and the ease with which it may be purchased in many parts of the country, or to be rid of it altogether. However, there are also many Americans who, despite the appalling death rate, feel that we have the right to own firearms.
Opponents of strict gun controls argue that the right to own firearms is guaranteed by the U. S. Constitution. The claim is made that, without firearms, we would be more vulnerable than ever to criminal violence. Moreover, they claim, we would be unable to defend ourselves if subversive elements, a would-be dictator, or some foreign intruder attempted to take hold of the country. The privately owned gun helped us to win our freedom in the first place, they say; it can help us preserve that freedom today.
Further, opponents of gun control tell us that gun-control laws don't work because the people who cause most of the trouble--the criminals--simply don't bother to obey them. But the proponents of control reply by producing statistics to show that control laws have kept the crime rates down in other nations. Strictly enforced controls, they believe, can do the same thing here.
The American public are divided in opinion about ______.
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