试题与答案

某同学在利用红色彩球(标记D)和绿色彩球(标记d)进行“性状分离比模拟实验”的过

题型:选择题

题目:

某同学在利用红色彩球(标记D)和绿色彩球(标记d)进行“性状分离比模拟实验”的过程中进行了以下操作,其中错误的做法是[ ]

A.在代表雌配子的小桶中放入两种彩球各10个

B.在代表雄配子的小桶中放入两种彩球各10个

C.在每次随机抓取彩球之前摇均小桶中的彩球

D.在抓取10次后记录并统计分析彩球组合类型比例

答案:

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某国有农场有土地48000亩,其中,耕地43000亩,1999年农场播种粮、豆、油、菜等作物52000亩,其中,粮豆播种面积为43000亩,粮豆播种面积中间套作为28000亩。由于土地条件较好,大部分都可以灌溉。1999年粮豆总产2279万公斤,为该场历史上最好的丰收年,使农场盈利比上年翻了一番。请根据上述资料回答下列问题:

反映土地利用程度的指标有()。

A.土地利用构成指数

B.土地复种指数

C.土地垦殖指数

D.土地间套作指数

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题型:单项选择题

When you first drift off into slumber, your eyes will roll about a bit, your temperature will drop slightly, your muscles will relax, and your breathing will become quite regular. Your brain waves slow down a bit, with the alpha rhythm predominating for the first few minutes. This is the first stage of sleep. For the next 30 minutes or so, you will drift down through Stage 2 and Stage 3. The lower your stage of sleep, the slower your brain waves will be. About 40-60 minutes after you lose consciousness, you will reach the last stage. Your brain waves will show the delta rhythm. You may think that you stay at this deep stage all the rest of the night, but that turns out not to be the case. About 80 minutes after you fall into slumber, your activity cycle will increase slightly. The delta rhythm will disappear, to be replaced by the activity pattern of brain waves. Your eyes will begin to dart around under your closed eyelids. This period of Rapid Eye Movements lasts for 8-15 minutes and is called REM sleep.
During both light and deep sleep, the muscles in your body are relaxed but capable of movement. As you slip into REM sleep, a very odd thing occurs -- most of the voluntary muscles in your body become paralyzed. Although your brain shows very rapid bursts of neural activity during REM sleep, your body is incapable of moving. REM sleep is accompanied by extensive muscular inhibition.

On the part of an average sleeper, there______of sleep in cycles.

A.is one stage

B.are two stages

C.are six stages

D.are four stages

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题型:单项选择题

对甲状旁腺的影像学检查下列哪项正确()

A.B超检查方便,灵活,经济。可获得颈部多个断面的图像。对于正常位置的甲状旁腺病灶容易检出,但异位甲状旁腺不易检出。检查结果与操作者熟练程度关系密切

B.CT层面厚度的选择及读片经验不足可致假阴性。颈动脉淋巴结或甲状腺结节可误为甲状旁腺。分辨率不及MRI

C.MRI具有灵活多变的采集序列,可显示胸骨后异位腺瘤。成像时间长,检查费用较高

D.核素显像对于检测在纵隔、气管与食管间、颌下等部位的异位甲状旁腺瘤有优势

E.以上都对

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