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问题 配伍题 B型题

白喉毒素致病机制是()
破伤风痉挛毒素致病机制是()

A．抑制易感细胞的蛋白质合成

B．破坏细胞膜使细胞裂解

C．阻断上、下神经元之间正常抑制性介质的传递，导致肌肉痉挛

D．抑制神经末梢释放乙酰胆碱，影响神经冲动的传递，导致肌肉迟缓型麻痹

E．激活细胞内腺苷酸环化酶，使cAMP的水平增高，使粘膜细胞的分泌功能增强

答案

参考答案：A,C

单项选择题

A


"In only six clays I lost seven pounds of weight. "
"Two full inches in the first three days!"
These are the kinds of statements used in magazine, newspaper, radio and television ads. , promising new shapes and new looks to those who buy the medicine or the device. The promoters of products say they can shape the legs, slim the face, smooth wrinkles, or in some other ways to add to beauty or desirability.
Often such products are nothing more than money-making things for their promoters. The results they produce are questionable, and some are dangerous to health.
To understand how these products can be legally promoted to the public, it is necessary to understand something of the laws covering their regulation. If the product is a drug, FDA (Food and Drug Administration)can require proof (证明) under the Food, Drug, and Cosmetic Act that is safe and effective before it is put on the market. But if the product is a device, FDA has no authority to require pre-marketing proof of safety or effectiveness. If a product already on the marker is a danger to health, FDA can request the producer or distributor to remove it from the market voluntarily, or it can take legal action, including seizure (查封) of the product.
One notable case a few years ago involved an electrical device called the Relaxacisor, which had been sold for reducing the waistline. The Relaxacisor produced electrical shocks to the body through contact pads. FDA took legal action against the distributor to stop the sale of the device on the grounds that it was dangerous to health and life.
Obviously, most of the devices on the market have never been the subject of court proceedings (法律诉讼), and new devices appear continually. Before buying, it is up to the consumer to judge the safety or effectiveness of such items.

It can be inferred that ads. mentioned in the text are ______.

A．objective

B．costly

C．unreliable

D．illegal
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单项选择题

在Windows 2000 Server系统下，从计算机的2个硬盘中各拿出100MB空间形成RAID1卷，并分配盘符D，那么D盘空间是（）

A．200MB

B．300MB

C．250MB

D．100MB
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