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问题 选择题

下列有关叙述正确的是

A．如图所示，测定中和热时，大小两烧杯间填满碎纸的作用只是固定小烧杯

B．若用50mL 0.55mo1·L—1的氢氧化钠溶液，分别与50mL 0.50mo1·L—1的盐酸和50mL 0.25mo1·L—1的硫酸充分反应，两反应测定的中和热不相等

C．在中和滴定实验中，滴定管用蒸馏水洗涤后，再用标准液润 洗，再加进标准液

D．进行中和滴定操作时，左手震荡锥形瓶，右手转动活塞控制液滴流速，眼睛要始终注视滴定管内溶液液面的变化

答案

答案：C

正确答案：C

A、不正确，起隔热作用；B、不正确，中和热是生成1molH2O放出的热量，应相等；C、正确，减小误差；D、不正确，眼睛要始终注视锥形迸内溶液颜色的变化

单项选择题

The field of medicine has always attracted its share of quacks and charlatans — disreputable women and men with little or no medical knowledge who promise quick cures at cheap prices. The reasons why quackery thrives even in modern times are easy to find.To begin with, pain seems to be a chronic human condition. A person whose body or mind "hurts" will often pay any amount of money for the promise of relief. Second, even the best medical treatment cannot cure all the ills that beset men and women. People who mistrust or dislike the truths that their physicians tell them often turn to more sympathetic ears.Many people lack the training necessary to evaluate medical claims. Given the choice between (a) a reputable physician who says a cure for cancer will be long, expensive and may not work at all, and (b) a salesperson who says that several bottles of a secret formula "snake oil" will cure not only cancer but tuberculosis as well, some individuals will opt for "snake oil".Many "snake oil" remedies are highly laced with alcohol or narcotic drugs. Anyone who drinks them may get so drunk or stoned that they drown their pains in the rising tide of pleasant intoxication. Little wonder that "snake oil" is a popular cure-all for minor aches and hurts! But let there be no misunderstandings. A very few "home remedies" actually work. However, most remedies sold by quacks are not only useless, but often can be harmful as well.

The sentence "pain seems to be a chronic human condition" means pain seems to________.

A．be very serious

B．be very difficult

C．last for a long time

D．be always happening
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单项选择题 A3/A4型题

患者女，54岁。发现左下牙龈菜花样溃疡2个月，无下唇麻木症状，活检诊为“鳞癌Ⅰ级”。查见溃疡3cm×2cm，小颌面顶部未触及明显肿大淋巴结。对该患者应首先补充的局部检查是（）。

A.CT

B.B超

C.颌骨X线片

D.核素骨扫描

E.PET
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