为研究植物的一些生理现象,如图所示,广口瓶内盛有少量澄清石灰水,内放一株绿色植物

题型:实验题

问题:

为研究植物的一些生理现象,如图所示,广口瓶内盛有少量澄清石灰水,内放一株绿色植物,瓶塞塞住,并用凡士林密封。

(1)要验证绿色植物的呼吸作用,需将装置放置在黑暗的环境中,目的是避免瓶内的植物进行__________作用,对实验结果产生干扰。

(2)在黑暗中放置较长时间后,发现广口瓶中澄清的石灰水变得__________,表明植物通过__________作用释放的__________与澄清石灰水发生了反应。

(3)然后,用浓NaOH溶液取代装置中的石灰水并将装置移到阳光下一段时间,取下其中一片叶进行脱色、漂洗、滴磺处理,结果发现叶片__________ (填“变蓝”或“不变蓝”),原因是瓶内缺乏__________,植物不能进行__________。

考点:探究实验:绿叶在光下制造有机物光合作用
题型:实验题

男性,35岁。发热,胸部持续性钝痛2天,胸痛于仰卧时加剧,用硝酸甘油无效,心音减低,伴舒张期附加音,BP110/80mmHg,下肢水肿,静脉压180mmH2O。ECG:ST段抬高,弓背向下,未见Q波。

最可能的诊断是哪个()

A.急性心肌梗死

B.缩窄性心包炎

C.变异型心绞痛

D.稳定型心绞痛

E.急性渗出性心包炎

题型:实验题

图中两条平行虚线之间存在匀强磁场,虚线间的距离为l,磁场方向垂直纸面向里。abcd是位于纸面内的梯形线圈,ad与bc间的距离也为l。t=0时刻,bc边与磁场区域边界重合,如图所示。现令线圈以恒定的速度v沿垂直于磁场区域边界的方向穿过磁场区域。取沿a→b→c→d→a的感应电流为正,则在线圈穿越磁场区域的过程中,感应电流I随时间t变化的图线可能是

[ ]

A.

B.

C.

D.

题型:实验题

女,28岁,14岁月经来潮,周期正常。现停经45天, * * 流血持续20天,时多时少,无腹痛。妇科检查:宫颈光滑,颈管内有透明分泌物,作涂片见羊齿植物叶状结晶,子宫前位正常大小,附件未及。可能的诊断是 ()

A.异位妊娠

B.流产

C.子宫内膜不规则脱落

D.无排卵性功血

E.黄体功能不足

题型:实验题

对于术前创伤失血量的估计,下列哪些是错误的()。

A.小量出血是指失血量占血容量的20%左右,临床症状不明显

B.中度出血是指失血量占血容量的20%~40%,临床休克症状明显

C.大量出血是指失血占血容量的40%~80%,出现明显衰竭症状

D.严重出血是指失血量占血容量的80%以上,处理不及时可转为不可逆休克

E.休克指数是指脉搏与收缩压的乘积

题型:实验题

My Views on Gambling
Most of life is a gamble. Very many of the things we do involve taking some risk in order to achieve a satisfactory result. We undertake a new job with no idea of the more indirect consequences of our action. Marriage is certainly a gamble and so is the bringing into existence of children, who could prove sad liabilities. A journey, a business transaction, even a chance remark may result immediately or ultimately in tragedy. Perpetually we gamble-against life, destiny, chance, the unknown, call the invisible opponent what we will. Human survival and progress indicate that usually we win.
So the gambling instinct must be an elemental one. Taking risks to achieve something is a characteristic of all forms of life, including humanity. As soon as man acquired property, the challenge he habitually issued to destiny found an additional expression in a human contest. Early may well have staked his flint axe, his bearskin, his wife, in the hope of adding to his possessions. The acquirement of desirable but nonessential commodities must have increased his scope enormously, while the risk of complete disaster lessened.
So long as man was gambling against destiny, the odds were usually in his favor, especially when he used commonsense. But as the methods of gambling multiplied, the chances of success decreased. A wager against one person offered on average even chances and no third party profited by the transaction. But as soon as commercialized city life developed, mass gambling become common. Thousands of people now compete for large prizes, but with only minute chances of success, while the organizers of gambling concerns enjoy big profits with, in some cases, no risk at all. Few clients of the betting shops, football pools, state lotteries, bingo sessions, even charity raffles, realize fully the flimsiness of their chances and the fact that without fantastic luck they are certain to lose rather than gain.
Little irreparable harm results for the normal individual. That big business profits from the satisfaction of a human instinct is a common enough phenomenon. The average wage-earner, who leads a colorless existence, devotes a small percentage of his earnings to keeping alive with extraordinary constancy the dream of achieving some magic change in his life. Gambling is in most cases a non-toxic drug against boredom and apathy and may well preserve good temper, patience and optimism in dreary circumstances. A sudden windfall may unbalance a weaker, less intelligent person and even ruin his life. And the line of something for nothing as an ideal evokes criticism from the more rigidly upright representatives of the community. But few of us have the right to condemn as few of us can say we never gamble-even it is only investing a few pence a week in the firm’s football sweep or the church bazaar "lucky dip."
Trouble develops, however, when any human instinct or appetite becomes overdeveloped. Moderate drinking produces few harmful effects but drunkenness and alcoholism can have terrible consequences. With an unlucky combination of temperament and circumstances, gambling can only become an obsession, almost a form of insanity, resulting in the loss not only of a man’s property but of his self-respect and his conscience. Far worse are the sufferings of his dependants, deprived of material comfort and condemned to watching his deterioration and hopelessness. They share none of his feverish excitement or the exhilaration of his rare success. The fact that he does not wish to be cured makes psychological treatment of the gambling addict almost impossible. He will use any means, including stealing, to enable him to carry on. It might be possible to pay what salary he can earn to his wife for the family maintenance but this is clearly no solution. Nothing-education, home environment, other interest, wise discouragement-is likely to restrain the obsessed gambler and even when it is he alone who suffers the consequences, his disease is a cruel one, resulting in a wasted, unhappy life.
Even in the case of the more physically harmful of human indulgences, repressive legislation often merely increases the damage by causing more vicious activities designed to perpetuate the indulgence in secret. On the whole, though negative, gambling is no vice within reasonable limits. It would still exist in an ideal society. The most we can hope for is control over exaggerated profits resulting from its business exploitation, far more attention and research devoted to the unhappy gambling addict and the type of education which will encourage an interest in so many other constructive activities that gambling itself will lose its fascination as an opiate to a dreary existence. It could be regarded as an occasional mildly exciting game, never to be taken very seriously.

Many people would like to give away a small sum of money because they constantly thing the donation may

A.not affect their general income.

B.bring them unexpected big sums of money.

C.help them preserve their temper and patience.

D.bring them some pennies from heaven.

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