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问题 单项选择题

用醇类溶剂提取法提取脂溶性生物碱的原理( )

A．脂溶性生物碱与酸成盐后易溶于水
B．脂溶性生物碱与酸成盐后不溶于水
C．脂溶性生物碱和生物碱盐都可溶于甲醇或乙醇
D．游离生物碱易溶于亲脂性有机溶剂
E．水溶液碱化后使生物碱游离析出

答案

参考答案：C

阅读理解与欣赏

阅读下文，回答问题。

　　扬州郭猫儿，善口技。庚申（清康熙十九年），余在扬州，一友挟猫儿同至寓。比晚酒酣，郭起请奏薄技，于席右设围屏，不置灯烛，郭坐屏后，立客静听。

　　久之，无声。少之，群鸡乱鸣，其声之种种各别。俄闻父呼其子曰：“天将明，可以宰猪矣。”其子起至猪圈中饲猪，则闻群猪争食声，吃食声，其父烧汤声，进火倾水声。其子遂缚一猪，猪被缚声，磨刀声，杀猪声，猪被杀声，出血声，燖（xún）剥声，历历不爽也。父又谓子：“天已明，可卖矣。”闻肉上案声，即闻有买卖数钱声，有买猪首者，有买腹脏者，有买肉者。正在纷纷争闻不已，砉（huā）然一声，四座俱寂。

1．根据上下文意思，解释下列加粗的字词。

（1）挟：________________

（2）同至寓：________________

（3）久之：________________

（4）争闻不已：________________

（5）四座俱寂：________________

2．从选文中我们可得知，口技表演者郭猫儿表演的这段口技的主要内容是什么？

______________________________________________________________

3．选文中作者一共写了哪几种声音？

______________________________________________________________

4．翻译句子。

群鸡乱鸣，其声之种种各别。

______________________________________________________________

5．本文与《口技》有哪些相同之处？

______________________________________________________________

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单项选择题

Questions 81-90 are based on the following passage.
It sounds like a science fiction, but researchers say it’s a scientific fact: Microscopic organisms dubbed "killer algae" are paralyzing fish with unknown toxins and then eating away at their flesh. They might be making people sick, too.
The name given to this single-cell organism, or dinoflagellate, is Pfiesteria piscimorte- literally, "fish killer. " It was discovered at North Carolina State University in 1988, but at the same time, few scientists believed in its existence, much less in its highly unusual predatory nature. But ongoing research has led to international acknowledgment of the phenomenon and, recently, research funding.
Seemingly prompted by an unknown substance secreted by fish, the aggressive creature swims into action. It sends neurotoxins into the water and air, paralyzing a fish’s nervous system, and causing it to gasp for air at the surface. Eventually the fish suffocates. The killer dinoflagellate then attaches itself to the fish and begins sucking away at its flesh. This macabre scenario may help solve several sea mysteries, such as why fishermen report seeing "fish walks" (fish trying to leave the water) and pools of dead fish with holes eaten through them.
Whether humans are affected by the dinoflagellate’s toxin remains to be seen. Researchers think it’s unlikely eating fresh fish are in danger, but anyone with frequent exposure to the creature could be in peril. Several researchers working with the algae have reported bouts of memory loss and disorientation.
To understand the killer algae further, scientists must fully characterize their toxin and determine what stimulates them to attack. They also need to know if the algae are hurting fish populations, and whether pollutants make them more likely to attack.

Researchers think that it is ______.

A．safe to eat fresh fish

B．dangerous to get close to the algae

C．safe to be near the algae

D．dangerous to expose the algae
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