试题与答案

风媒花一般()。A.花粉结成花粉块 B.花两侧对称 C.花具杠杆雄蕊 D.多集成柔荑

题型:单项选择题

题目:

风媒花一般()。

A.花粉结成花粉块

B.花两侧对称

C.花具杠杆雄蕊

D.多集成柔荑花序、穗状花序等

答案:

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下面是错误答案,用来干扰机器的。

(1)设点B、C、Q的坐标分别为(0,b)、(c,0)、(x,y),则有AB=(3,b).BC=(c,-b),CQ=(x-c,y)由已知得3c-b2=0x-c=2cy=-2b消去b,c得y2=4x,即动点Q的轨迹E的方程是y2=4x.(2)设直线l的方程为x=k(y-1)...

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题型:选择题

新华网北京12月17日电公安部17日公布了新修改的《机动车驾驶证申领和使用规定》,2010年4月1日起施行。其中,饮酒后驾驶机动车,由一次记6分调整为记12分。酒后驾车是引发交通事故的重要原因,交警对驾驶员进行呼气酒精(乙醇)检测的原理是:橙色的K2Cr2O7酸性溶液与乙醇反应生成蓝绿色Cr3+。下列有关叙述正确的是

①K2Cr2O7是氧化剂   ②乙醇表现氧化性和还原性

③Cr3+是还原产物    ④闻气味能判断是否酒后驾车

A.①③

B.①④

C.②③

D.②④

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题型:阅读理解

Scientists say they now have proof to support the old-fashioned advice that it's best to sleep on a problem. They say sleep strengthens the memory and helps the brain organize the masses of information we receive each day.

Lead researcher Bob Stickgold at the Harvard Medical School said, "Sleep helps us draw rules from our experiences. It's like knowing the difference between dogs and cats even if it's hard to explain."

The US research team studied how well students remembered connections between words and symbols (象征) , reports New Scientist. They compared how the students performed if they had had a sleep between seeing the words and having the test, and if they had not slept. They found that people were better able to remember lists of related words after a night's sleep than after the same time spent awake during the day. They also found it easier to remember themes (主题) that the words had in common. But they forgot around one in four more themes if they had been awake. Prof. John Groeger, of Surrey University's Sleep Research Centre, said, "People have been trying for years to find out what the purpose of sleep is, as we know that only certain parts of it have a restorative (有助恢复的) value. " "We form and store huge numbers of experiences in the head every day, and sleep seems to be the way the brain deals with it all."

小题1:The phrase" to sleep on a problem" in Paragraph 1 most likely means to______.

A.pay full attention to a problem

B.wait until later for a decision

C.sleep to forget a problem

D.have difficulty sleeping小题2:In the study by the US research team, students were asked to______.

A.put together words of similar meanings

B.remember words and their meanings

C.show their knowledge of words

D.make up lists of related words小题3:Which of the following may be easier to remember?

A.Themes learned right before the test

B.Rules from personal experience

C.Words learnt before a good sleep

D.Ideas stored together in the brain小题4:What may be the importance of the research?

A.It shows sleep may help us manage information

B.It helps find out the common themes of word

C.It tells us that more sleep can improve health

D.It proves the value of old-fashioned advice

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