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问题 多项选择题

高血压患者麻醉中的一些描述哪些是正确的()

A．常温下控制性低血压应<30%收缩压

B．局麻药中不宜加用肾上腺素

C．一般不宜采用腰麻

D．上腹部手术慎用硬膜外麻醉

E．静吸复合麻醉避免麻醉过浅

答案

参考答案：A, B, C, D, E

单项选择题

已知氧化还原电对：选择一种氧化剂，在标准状态下能将上面三个电对中的还原态氧化成其氧化态（）。

A.

B.

C.

D.
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单项选择题

Natural flavorings and fragrances are often costly and limited in supply. For example, the vital ingredient in a rose fragrance is extracted from natural rose oil at a cost of thousands of dollars a pound; an identical synthetic substance can be made for 1% of this cost. Since the early twentieth century, success in reproducing these substances has created a new industry that today produces hundreds of artificial flavors and fragrances.
Some natural fragrances are easily synthesized; these include vanillin, the aromatic ingredient in vanilla, and benzaldehyde, the aromatic ingredient in wild cherries. Other fragrances, however, have dozens, even hundreds of components. Only recently has it been possible to separate and identify these ingredients by the use of gas chromatography and spectroscopy. Once the chemical identity is known, it is often possible to synthesize them. Nevertheless, some complex substances, such as the aroma of fresh coffee, have still not been duplicated satisfactorily.
Many of the chemical compounds making up these synthetics are identical to those found in nature, and are as harmless or harmful as the natural substances. New products must be tested for safety, and when used in food, must be approved by the U.S. Food and Drug Administration.
The availability of synthetic flavors and fragrances has made possible a large variety of products, from inexpensive beverages to perfumed soap to used cars with applied "new car odor."

Which of the following is NOT true according to the last paragraph

A．Synthetic fragrances can be used to make a used car smell like a new one.

B．Synthetic flavors and fragrances have added to the varieties of products.

C．Lemon soap is made out of some delicious lemon.

D．It is likely that a bottle of orange juice is synthesized.
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