题干

某生物实验小组同学发现,花生果实有大小品种,即使就是大花生也有大小之分,于是他们提出假设、设计实验、进行论证,分别仔细选出5粒大花生和5粒小花生,进行测量,统计数据,见下表。请你回答下列问题。

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同类题3

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    Every student is eager to achieve the goals they have set earlier. Here is what experts advise on how to do it.

    ____When it comes to choosing your goal, make sure that it states exactly what it is that you want to achieve. If your goal seems too big, divide it into simpler, easier tasks.

    Write down your goal. You can write it in a journal or write it on a sticky note. Writing keeps your memory fresh and helps you clear up the clutter (杂乱) in your brain. Try to keep a journal or a diary.

    Break your goal down. By chopping your goal up into manageable sections, it allows you to mentally make your way through the goal until the end of a year.____Therefore, you're far less likely to give up or dodge (逃避) your goal by taking shortcuts or refusing to do anything.

    Put a brake (阻力) on distractions. Turn off all distractions like TV, the Internet, your phone and every other gadget you have at home.____

    Make it happen.____ Thinking is a useful start but thinking doesn't do the heavy work and thinking certainly won't move mountains. Go out every morning knowing what you need to do and then do it!

    Stay positive. Keep saying that you can do it. Stay motivated and be confident.

    Reward yourself.____ Every once in a while, if you complete a goal, treat yourself than extra bar of chocolate or make time to read that book you've been wanting to read since two months ago.

A. Don't think to yourself that over time you will manage to do it

B. Choose a specific, realistic and important goal

C. It is necessary to choose a proper way to finish the goals

D. Carry out your goal as soon as possible

E. Don't be too hard on yourself

F. This method makes it easier to deal with

G. Keep emails, phone calls, texts, etc. to a minimum.

同类题4

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月  亮

    中秋赏月,忽有友人相问:“月亮生于何年,来自何方?”

    在天文学上,这个问题称为“月球的起源”。其答案虽然至今尚付阙如,但是天文学家们却根据众多的天文观测事实,对月球的身份作了合乎逻辑的推测。总的说来,大致有三种可能:月球若不是地球的妻子,那便是地球的姐妹,或者是地球的女儿。

    你看,月球的平均密度是每立方厘米3.34克,只相当于地球密度的五分之三,而且两者的化学成分又大不相同,因此情况很可能是这样:当46亿年以前,我们这个太阳系从一大团星云物质脱胎而出时,月球和地球分别处在相去甚远的不同部位,它们各由当地的不同物质所形成。另一方面,月球的平均密度又与小行星的乃至陨星的密度十分相近。所以,它原先很可能是一颗小行星,在它围绕太阳运行的过程中一度接近地球,并为后者的引力所俘获,而成为地球的卫星。这种学说称为“俘获说”。倘若情况果真如此,那么,将地球与月球比作邂逅相遇遂成天作之合的夫妻,岂不是再妙不过了吗?

    但是,地球的直径只是月球直径的3.7倍,相去并不悬殊;况且,迄今为止人们所知的小行星无一例外都比月球小得多;所以,像地球这么一颗并不很大的行星,偏偏要俘获一个像月球这么大的小行星亦实非易事。于是,有一部分天文学家认为:在太阳系形成之际,地球和月球由同一块尘埃云凝聚而咸。它们的平均密度和化学成分之所以不同,乃是由于原始星云中的金属成分在行星形成之前已凝聚咸团。 这种学说称为“同源说”。如此看来,月亮岂不就是地球的妹妹?

    最后一种推测更具有戏剧性:在40多亿年前太阳系形成之初,地球月球原为一体。当时地球处于高温熔融状态, 自转很快;天长日久,便从其赤道区飞出一大块物质,形成了月球。太平洋便是月球分裂出去的残迹。这种学说称为“分裂说”。你看,月亮岂不及成了地球的女儿?不过,这种理论却面临着许多难题,比方说,它有一个必然的推论,即月球的位置应该处在地球的赤道面上,而实际情况却并非如此,现在,赞成这种学说的人已经比较少了。

    可爱的月亮啊,你究竟是谁?你尽可以讳莫如深,人类却总有一天会掀开你的神秘面纱,把你的真相查个水落石出!