一般植物叶片的上、下表皮都有气孔,但往往上表皮的气孔比下表皮的气孔少,原因是[

题型:选择题

问题:

一般植物叶片的上、下表皮都有气孔,但往往上表皮的气孔比下表皮的气孔少,原因是[ ]

A.上表皮气孔少可以减少水分的散失

B.下表皮气孔多可以吸收更多的二氧化碳

C.下表皮气孔多可以加速水分的散失

D.上表皮气孔少可以减少氧的散失

考点:叶片的结构
题型:选择题

由于患者周围循环不良,所致液体滴流不畅应()。

A.更换针头重新穿刺

B.另选血管重新穿刺

C.调整针头位置或适当变换肢体位置

D.提高输液瓶位置

E.热敷注射部位

题型:选择题

进行下列实验而制作临时标本时,需滴入生理盐水的是[ ]

A.观察气孔的结构  

B.观察洋葱表皮细胞的质壁分离和复原

C.观察人体口腔上皮细胞   

D.观察蛔虫卵的结构

题型:选择题

经过一阶段治疗,症状缓解后,首选的康复预防措施为

A.增加营养,增强抵抗力

B.禁止弯腰活动

C.减轻体重

D.腰背肌肉力量锻炼

E.下肢肌力锻炼

题型:选择题

Most people have no idea of the hard work and worry that goes into the collecting of those fascinating birds and animals that they pay to see in the zoo. One of the questions that is always asked of me is (67) I became an animal collector in the first (68) . The answer is that I have always been interested in animals and zoos. According to my parents, the first word I was able to say with any (69) was not the conventional "mamma" or "daddy", (70) the word "zoo", which I would (71) over and over again with a shrill (72) until .someone, in order to (73) me up, would take me to the zoo. When I (74) a little older, we lived in Greece and I had a great (75) of pets, ranging from owls m seahorses, and I spent all my spare time (76) the countryside in search of fresh specimens to (77) to my collection of pets. (78) on I went for a year to the City Zoo, as a student (79) , to get experience of the large animals, such as lions, bears, bison and ostriches, (80) were not easy to keep at home. When I left, I (81) had enough money of my own to be able to (82) my first trip and I have been going (83) ever since then. Though a collector’s job is not an easy one and is full of (84) , it is certainly a job which will ap peal (85) all those who love animals and (86) .

A.living

B.cultivating

C.reclaiming

D.exploring

题型:选择题

若有两个字符串s1=“12345”,s2=“34”,执行s=Instr(s1,s2)后,s的值为( )。

A.2

B.3

C.4

D.5

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