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问题 单项选择题

在一个细胞周期内，T和U两种碱基被大量利用时，细胞的生理活动是（）

A．DNA分子正在复制

B．正在大量合成转运RNA

C．正在大量合成蛋白质

D．正处于分裂间期

答案

参考答案：D

问答题

用如图11所示的水杯盛水，经常会遇到这样的情况，往杯里装入大半杯热水，拧紧杯盖，过较长一段时间后，杯盖会很难拧下来。(1)简要回答产生这一现象的原因。 (2)请设计一种打开杯盖的方法，并说出该种方法用到的物理原理。(不能损坏杯子)
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填空题



Despite (1) that alcoholic beverages may (2) , a leading medical expert is advising: don’t (3) just yet.
Anybody who’s ever worked in a hospital sees the hospital is full of patients that have (4) disease, but the hospital is not full of patients that have disease related to cholesterol and (5) .
In an (6) in the current New England Journal of Medicine, Dr. Goldberg of Columbia University said it is time to see (7) prevents heart disease. Such a study would give (8) to one group of heart disease patients and not to another, and see (9) .
In the latest study, which followed (10) over a 12-year period, researchers found that those who drank (11) drinks per week (12) of heart attack by (13) compared to (14) .
The lead author, (15) Kenneth Mukamal of Beth Israel Deaconess Medical Center in Boston, insists his study is (16) . For one thing, other studies have not looked at (17) .
Dr. Mukamal says (18) also appear to settle which alcoholic beverage are (19) . "Beer and spirits, beer and liquor, were most ply (20) ."
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