It can be learned from the passage that about four billion years ago ______.A. the earth was in molten stateB. the earth surface temperature was above 100℃C. the earth surface temperature was below 100℃D. rain water could remain on the earth

Passage 2
Americans don’t like to lose wars．Of course，a lot depends on how you define just what a waris．There are shooting wars—the kind that test patriotism and courage--and those are the kind atwhich the U．S．excels．But other struggles test those qualities t00．What else was the GreatDepression or the space race or the construction of the railroadsIf American indulge in a bit offlag--when the job is done，they earned it．
Now there is a similar challenge--global warmin9．The steady deterioration of the very climateof this very planet is becoming a war of the first order，and by any measure，the U．S．is losing．
Indeed，if America is fighting at all，it’sfighting on the wrong side．The U．S．produces nearly aquarter of the world’s greenhouse gases each year and has stubbornly made it clear that it doesn’tintend to do a whole lot about it．Although l 74 nations approved the admittedly flawed Kyotoaccords to reduce carbon levels，the U．S．walked away from them．There are vague promises ofmanufacturing fuel from herbs or powering cars with hydrogen．But for a country that tightly citespatriotism as one of its core values，the U．S．is taking a pass on what might be the most patrioticstruggle of all. It′ s hard to imagine a bigger fight than one for the survival of a country′ s coasts andfarms, the health of its people and stability of its economy.
The rub is, if the vast majority of people increasingly agree that climate change is a globalemergency, there′s far less agreement on how to fix it. Industry offers its plans, which too oftenwould fix little. Environmentalists offer theirs, which too often amount to native wish lists that couldweaken America′ s growth. But let′ s assume that those interested parties and others will always bentthe table and will always demand that their voices be heard and that their needs be addressed. Whatwould an aggressive, ambitious, effective plan look like--one that would leave the U.S. bothenvironmentally safe and economically sound
Halting climate change will be far harder. One of the more conservative plans for addressingthe problem calls for a reduction of 25 billion tons of carbon emissions over the next 52 years. Andyet by devising a consistent strategy that mixes short-time profit with long-range objective andblends pragmatism with ambition, the U.S. can, without major damage to the economy, help halt theworst effects of climate change and ensure the survival of its way of life for future generations.
Money will do some of the work, but what′s needed most is will. "I′m not saying the challenge isn′talmost overwhelming," says Fred Krupp. "But this is America, and America has risen to thesechallenges before."
The paragraphs immediately following this passage would most probably deal with__________.

A.the new book written by Fred Krupp

B.how America can fight against global warming

C.the harmful effects of global warming

D.how America can tide over economic crisis

资料：The personal computer was a revolution in information technology that spawned a $50 billion hardware business, with another $30 billion in software and peripherals （eg. mouse, keyboard, printer, etc.） by 1991. During its short 15 years, the industry evolved through three successive periods. During its first 5 to 6 years, it was characterized by explosive growth and multiple, small competitors vying for a piece of the market. From 1981 to 1985, the industry became a battle for standards and retail shelf space. The third era was one of increasing fragmentation. From 1986 through 1991-1992, new manufacturers from around the world grabbed from the industry leaders as new channels of distribution emerged and product innovation as well as revenue growth slowed.
During the early years of the industry, venture capital in the U.S. encouraged the entry of new firms that offered products in every conceivable shape and size. By 1980, new entrants flooded the market, prompting distinct standards and unique technical features. Almost every firm had a different configuration of hardware and software. The first PC had relatively little speed or memory. However, even these early computers allowed managers to perform tasks that were very time consuming.

What was impossible during the early years of the industry?

A.Sharing applications between machines.
B.Programming on the computer.
C.Writing contracts on the computer.
D.Buying keyboards and printers.

资料：The personal computer was a revolution in information technology that spawned a $50 billion hardware business, with another $30 billion in software and peripherals （eg. mouse, keyboard, printer, etc.） by 1991. During its short 15 years, the industry evolved through three successive periods. During its first 5 to 6 years, it was characterized by explosive growth and multiple, small competitors vying for a piece of the market. From 1981 to 1985, the industry became a battle for standards and retail shelf space. The third era was one of increasing fragmentation. From 1986 through 1991-1992, new manufacturers from around the world grabbed from the industry leaders as new channels of distribution emerged and product innovation as well as revenue growth slowed.
During the early years of the industry, venture capital in the U.S. encouraged the entry of new firms that offered products in every conceivable shape and size. By 1980, new entrants flooded the market, prompting distinct standards and unique technical features. Almost every firm had a different configuration of hardware and software. The first PC had relatively little speed or memory. However, even these early computers allowed managers to perform tasks that were very time consuming.

When did the PC industry start?

A.Around 1981.
B.Around 1986.
C.Around 1976.
D.Around 1992.

资料：The personal computer was a revolution in information technology that spawned a $50 billion hardware business, with another $30 billion in software and peripherals （eg. mouse, keyboard, printer, etc.） by 1991. During its short 15 years, the industry evolved through three successive periods. During its first 5 to 6 years, it was characterized by explosive growth and multiple, small competitors vying for a piece of the market. From 1981 to 1985, the industry became a battle for standards and retail shelf space. The third era was one of increasing fragmentation. From 1986 through 1991-1992, new manufacturers from around the world grabbed from the industry leaders as new channels of distribution emerged and product innovation as well as revenue growth slowed.
During the early years of the industry, venture capital in the U.S. encouraged the entry of new firms that offered products in every conceivable shape and size. By 1980, new entrants flooded the market, prompting distinct standards and unique technical features. Almost every firm had a different configuration of hardware and software. The first PC had relatively little speed or memory. However, even these early computers allowed managers to perform tasks that were very time consuming.

What happened in the third era?

A.The small companies experienced a harsh life.
B.People preferred PCs of big brands.
C.The big companies didn’t earn as much as they did in the past two periods.
D.The companies made standards on the configuration.