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The doctor warns Jack smoking because it is bad for his health.
A. to stop B. not to stop C. stopped D. not stopped
九年级英语单选题简单题查看答案及解析
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The doctor warns Jack _____________stop _____________because it is bad for his health.
A.to; smoking B.not; to smoke C.to; to smoke D.not to; smoking
九年级英语单选题中等难度题查看答案及解析
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The doctor warns Tom smoking because it is bad for his health.
A. to stop B. not to stop
C. stopped D. not stopped
九年级英语单项填空中等难度题查看答案及解析
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— Why don' the doctors stop ________ lunch?
— Because they are busy ________ a patient.
A.to have; to save B.having: saving C.to have; saving D.having; to save
九年级英语单选题中等难度题查看答案及解析
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(2018东营改编)—Jack, the Maldives(马尔代夫)may ________ because of the rising sea levels.
—God! We must do something to stop that happening.
A.rise B.appear C.grow D.disappear
九年级英语单选题中等难度题查看答案及解析
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The idea that red means stop and green means go has influenced our lives in more ways than just traffic signals(信号). We have been taught from a young age that the color red means danger and green means it's okay to move forward. But why were those colors chosen for traffic lights in the first place? For something we have to look at every day, why couldn't they have been prettier colors?
Well, it's important to know that before traffic lights for cars, there were traffic signals for trains. At first, railway companies used red to mean stop, white to mean go, and green to mean warn. As you could imagine, trains ran into a few problems with white meaning go. For example, one train mistook a bright star for a white light and something unexpected happened. Because of that, railway companies finally moved green meaning go and used yellow to mean warn. And it's been that way ever since.
Red has always been a color that meant danger, long before cars were even around. This most likely started because it's the color with the longest wavelength(波长) so it can be seen somewhere farther than other colors.
But, believe it or not, yellow was once used to mean stop. Back in the 1900s, some stop signs were yellow because it was too hard to see a red sign in a poorly lit area. Finally, highly reflective materials(高反射材料) were developed and red stop signs were born. Since yellow can be seen well at all times of the day, school zones, some traffic signs, and school buses continue to be painted yellow.
So next time you're impatiently waiting at a traffic light, don't get so mad at them, they've certainly come a long way.
What does the text mainly tell us?
A.How important traffic lights are.
B.Which color has the longest wavelength.
C.What red, yellow and green can be used for.
D.Why traffic lights are red, yellow and green.
九年级英语阅读单选中等难度题查看答案及解析
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The doctor warned the patient oily food after the operation.
A.not to drink B.to drink C.not to eat D.not eat
九年级英语单选题中等难度题查看答案及解析
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The doctor warned us ______ the ______ of the germs(病菌) by cleaning our hands from time to time.
A. controlling, spread
B. to control, spread
C. to control, development
九年级英语单项填空中等难度题查看答案及解析
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(2017·芜湖29中四模)The doctor warned us ________ more fruit and vegetables instead of meat.
A. eat B. eating
C. to eat D. to eating
九年级英语单选题简单题查看答案及解析
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There are some dangerous fish in the river, and I’ve warned Jack______ here.
A. not to swim B. to not swim
C. swim not to D. to swim not to
九年级英语单项填空中等难度题查看答案及解析