单项选择题

Today we think of automobiles as a necessity, but at first the automobile was a luxury that only the rich could afford. In 1899, only 600 were built and sold. By 1925, the number approached 20 million. Today you can choose from a huge number of models, some costing 25 times of others. It is said that there are enough motor vehicles in Great Britain and America to carry their combined population.
Today we can say that much of the world runs on wheels. The four rubber tires of automobile move us from work to play. Wheels spin, and people drive off to their jobs. Tires turn, and they go shopping. Hub-caps whirl, and the whole family goes for a drive in the country.
In addition to automobile, other types of motor vehicles shape our lives. Public buses provide quick and inexpensive transportation. No matter whether you are traveling 500 miles from one city to another, or just going across town, imagine what your life would be like without buses. Trucks also help us in many ways. It is usually cheaper to send goods by truck than by air or train. And because there are many more highways than there are railways, trucks can go to places that trains could not reach. Huge tractor trailers carry goods thousands of miles from Europe to Saudi Arabia. Small pick-up trucks help farmers in every country get their produce to market.
The increased use of automobiles has brought a corresponding increase in auto-mobile-related problems such as traffic accidents and traffic congestion. One of the most serious results of our dependence on the automobile is air pollution. Automobiles pump hundreds of pounds of carbon monoxide and other poisonous gases into the air every day. Usually these gases do no immediate damage. However, under certain weather conditions, they may form clouds which cover the skies of large urban areas, threatening the lives of people, especially the sick and the old.
In the past fifteen years people have become increasingly worried about the effects of air pollution. Therefore, some governments have required automobile manufacturers to find a solution to this problem. As a result, many new cars today have antipollution devices which decrease the amount of pollutants released into the air.

How many types of motor vehicles are mentioned in this passage()

A. 5
B. 4
C. 9
D. 6

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单项选择题
According to the article, the California energy commission has received 200 project applications in one month. If that rate continues, approximately how many applications will they receive this entire year A. 2,400. B. 1,200. C. 200. D. 3,600.
Alternative energy is even more attractive, thanks to a state rebate program. So far this month, California’s energy commission has received 200 project applications. That is more than the number of applications all last year.
Putting in a solar roof is still a relatively expensive proposition. This project cost around 45,000 dollars. Even taking into account the state subsidy of 12,000 dollars, that leaves a net cost to the homeowner of around 33,000 dollars.
Sally says, "We were happy to find out that, eventually, the system should pay for itself, you know 20-years, maybe."Aaron Wellendorf has had a p-v (or photovoltaic generator) for more than a year. Like most solar systems, his is not off the grid completely and the utility still kicks in at night, or when there’s no sun. But when there is bright light, things change.
Wellendorf says, "I’m turning my meter backward with extra power that I’m generating." Backward
That’s right! Wellendorf’s meter tracks how much power goes back into the utility grid. Last year all he paid for electricity was a service charge. That charge was around five dollars a month.
In fact, even after powering his super-efficient household appliances and his converted electric track, Wellendorf generated a net surplus of more than 2,000-kilowatt hours.
Unfortunately, state law doesn’t require the utility to pay him for that. Wellendorf says, "I don’t get it in money, I just get the satisfaction of helping out the power grid."And, he gets the satisfaction of being energy self-sufficient.