单项选择题：上提管柱时，产生的抽汲力能导致井底压力（）。A、升高 B、降低 C、不变 D、为零

题型：单项选择题

A few years ago, Dave Stirling had the idea of selling CDs over the Internet. The business he started from his home in Ohio, the USA, now sells 500,000 CDs a year and has made him into a millionaire(百万富翁)at the age of 24.

“I could see that this was the future of shopping,” says Stirling. “Why should you pay $15 for a CD and spend the time and the money getting into the store and parking your car? You can have the same CD for half of the price by clicking(敲击)on your computer. And we can find any CD you want and bring it to your door in 24 hours!”

According to Stirling, this is the only beginning, “I believe that one day we’ll do our shopping over the net: it’s easier, quicker and cheaper. Shops and supermarkets will be the past.”

小题1:Dave Stiring started his business from______.

A．his home

B．his company

C．the office

D．the country小题2:How has Stirling become so rich?

A．By making ice cream.

B．By making advertisements.

C．By selling ideas to others.

D．By selling CDs over the Internet.小题3:If you pay $15 for a CD in the store, how much should you pay for it over the net?

A．$15.

B．$12.

C．$7.5.

D．$30.小题4:By shopping over the net, you won’t_____.

A．spend the time and the money

B．drive your car any more

C．click on your computer

D．get into the store by yourself小题5: What can we learn from the passage?

A．More than half of the Americans prefer to shop over the net.

B．Shops and supermarkets will be the past in the future.

C．Some people don’t like to go shopping over the Internet.

D．It’s easier, quicker and more expensive to do our shopping over the net.

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上提管柱时，产生的抽汲力能导致井底压力（）。A、升高 B、降低 C、不变 D、为零

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