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问题 单项选择题

A、B、C和D四种材料，其拉伸时的应力应变曲线分别如图5-14所示，问：

塑性最好的材料是（）.

A.A

B.B

C.C

D.D

答案

参考答案：C

填空题

Part 4


Questions 26-45


·Read the following passage and decide which answer best fits each space.
·Forquestions26-45, markoneletterA, B, C or D on the Answer Sheet.
Both (26) and zoology are parts of a more general field of science, biology. The two are studies of (27) things, which share certain characteristics, (28) they are plants or animals. Botany deals with plants, whose organisms that can (29) their own food by the use of sunlight. Zoology on (30) hand, deals with animals, those organisms that cannot manufacture their own food and are thus dependent (31) plants for their food.
(32) plants and animals share many abilities, the extent (33) which plants can exercise some of those abilities is (34) . For example, both plants and animals need food, water, and warmth for growth, (35) plants can move to (36) those needs only by the slow extraction of their leaves and roots, while animals can move relatively (37) distances in relatively little time. When an animal is hurt with needle, the animal will (38) the part of the body (39) . This ability to draw back (40) pain or irritation, called irritability, is found only to a very limited extent in plants.
If plants (41) the same (42) as animals, animals would have had a more difficult time finding food. If animals were as limited as plants, they might (43) a means of manufacturing their own food, as plants do now. The world would be a very different place (44) it is if the characteristics of plants and animals were (45)

A．on

B．in

C．at

D．with
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单项选择题 A1/A2型题

左旋多巴可以治疗肝性脑病的机制是（）

A.在肝脏中经脱羧转变为多巴胺

B.在中枢经脱羧转变为多巴胺

C.在中枢增加NA合成而起作用

D.在中枢直接发挥作用

E.改善肝功能
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