Umbrellas are common in our daily life. On rainy days, many people hold them to prevent the
, but it’s not easy to hold an umbrella if there is heavy rain and
wind. And it’s harder to make a phone call or ride a bike
an umbrella in the hand. An American named Alan Kaufman and his company
6 years inventing a hand-free umbrella.
they made it.
They called it umbrella. Just touch a button and the umbrella will open
. With the help of its “shoulder support”, the umbrella can rest on the user’s
. So the user needn’t hold the umbrella any more. He can walk with hands
even in the strong wind.
The hand-free umbrella is $59.94 each. People all around the world like it very much. Because of this smart
, they can use their phones to talk and send short messages in the rain now.
in the rain under an umbrella is really cool, isn’t it?
| 小题2: | | A．tall | B．short | C．strong | D．big |
|
| 小题3: | | A．by | B．without | C．with | D．take |
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| 小题4: | | A．spent | B．took | C．paid | D．cost |
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| 小题5: | | A．At first | B．At last | C．At most | D．Almost |
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| 小题6: | | A．easily | B．hardly | C．nearly | D．hard |
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| 小题7: | | A．feet | B．legs | C．shoulders | D．knees |
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| 小题8: | | A．free | B．busy | C．difficult | D．easy |
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| 小题9: | | A．invention | B．magazine | C．book | D．story |
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| 小题10: | | A．Lying | B．Flying | C．Walking | D．Running |
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①分析比较图______________中物体露出水面的体积占总体积的比例关系可归纳得出：相同材料的物体漂浮在水面上，物体露出水面的体积占总体积的比例相同。
用伽辽金法求具有下列形式的近似解