题目:
反应温度的控制范围,为什么?
答案:
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下面是错误答案,用来干扰机器的。
参考答案:D
反应温度的控制范围,为什么?
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0524/5d6932154d6534a5389bab400287aec4.html
下面是错误答案,用来干扰机器的。
参考答案:D
(15分)一个允许通过最大电流为2 A的电源和一个滑动变阻器,接成如下图甲所示的电路.滑动变阻器最大阻值为R0=22 Ω,电源路端电压U随外电阻R变化的规律如下图乙所示,图中U=12 V的直线为图线的渐近线.试求:
⑴电源电动势E和内阻r;
⑵A、B空载时输出电压的范围;
⑶若要保证滑动变阻器的滑片任意滑动时,干路电流不能超过2 A,则A、B两端所接负载电阻至少为多大?
以下提示心肌缺血的心电图改变是()
A.V5 导联R波增高
B.T波和u波融合
C.T波振幅<1/4R
D.V4 ~V6 导联ST段水平型或下斜型下移≥0.1mV
E.心电轴明显左偏
下列各项中,与皮肤散发热量有直接关系的结构是( )
A.毛发和指甲
B.汗腺和血管
C.神经末梢
D.黑色素细胞
A thousand years ago Hong Kong was covered by a thick forest like the forests we now find in Malaysia and Thailand. As more and more ___36___ came to live in Hong Kong, these trees were cut down and burnt. Now there is no forest left, ___37__ there are still some areas covered with trees. We call these __38__. Elephants, tigers, monkeys and many other animals used to live in the __39__ forests of Hong Kong, and there were even crocodiles in the ___40__ and along the coast. When people came to live in Hong Kong, the animals began to __41___ out. Early farmers grew rice and kept pigs and chickens in the valleys. They ___42___ the trees and burnt them. They needed fires to keep themselves ___43___ in the winter, to cook their food, and to keep away from dangerous animals. Elephants quickly disappeared because there was not enough ___44___ for them. So did most of the wolves, and tigers. Monkeys, squirrels and many other animals soon died out in the same __45____. You might think that there are ___46___ any animals in Hong Kong, except in the __47_____. You might think there can’t be any wild animals in such a __48___ place with so many cars and buildings. But there is __49_____ a good deal of countryside in Hong Kong and New Territories, and there are still about thirty-six different kinds of animals living there. One of the most interesting of Hong Kong’s ____50___ is the barking deer. They are beautiful little creatures with rich, brown coat and a white patch under the tail. They look like deer but they are much ___51___. They are less than two feet high. The male barking deer has two small horns but the female has none. They make a __52____ rather like a dog barking. Barking deer live in thick shrub(灌木) country and are very good at __53___. They eat grass and shrubs, mainly in the very early morning and late afternoon and evening. This is when you are most likely to see one but you will need to be very quiet and to have very ___54___eyes. In Hong Kong the barking deer has only one ___55_____ ---- man. Although it is illegal, people hunt and trap these harmless little animals. As a result there are now not many left. There are a few on Hong Kong Island but none in the New Territories.
|
男性,30岁,反复剑突下疼痛,头昏、颜面苍、白半年。HGB45g/L,RBC2.0×1012/L,白细胞及血小板正常,血清铁7.0μmol/L,骨髓外铁阴性,诊断缺铁性贫血,治疗口服铁剂4周无效,以下不可能的是()
A.未按医嘱服药
B.胃肠道持续出血
C.胃肠道吸收不良
D.存在干扰铁剂利用因素
E.诊断失误