基因自由组合定律的实质是（） A.受精时，雌雄配子自由组合 B.减数分裂中，非等位基

实物交割是了结商品期货合约的一个必经环节。（）

只催化电子转移的酶类是（）

A.加双氧酶

B.加单氧酶

C.不需要氧脱氢酶

D.需氧脱氢酶

E.细胞色素与铁硫蛋白

国家助学贷款的贷款额度最高不超过( )元。

A．(A) 2000

B．(B) 5000

C．(C) 6000

D．(D) 10000

It took courage to stand up at work. Now more and more people like to have a change and stand up when they are on something important. Standing up is popular. Medical researchers have found that people who stand at work tend to be much healthier than those who sit.

In the last few years, many office supply companies have begun to sell the adjustable- height desk. These so- called “ sit/ stand” models are equipped with an electric motor that lets them shift from chair height to person height at the push of a button. Unfortunately, they’re regarded as specially furniture. Sit/ stand desks tend to be expensive, hard to find and not easy to test it in person.

When you worked standing up, your mind was more excited and new ideas kept coming out. This is because when you’re standing, you feel a bit unchained from your desk. If you got stuck on a word or sentence as you wrote, you found yourself shaking your arms, bouncing on your feet or stepping away from the desk for a bit------ things you couldn’t do in a chair. Often, standing up seemed to relax your mind enough for you to get over creative barriers.

There’s one other thing about standing for a long time;  you tended to get hungrier than you do when you sit on a chair. That felt like confirmation of the stand-up advocates’ belief that you burn more calories when you stand than when you sit. For this reason alone, I’m hoping that sit/ stand desks one day hit the mainstream, with mass- market furniture companies making many low- priced versions. We could all do with a bit more standing up.

小题1:We can learn that the adjustable- height desk is_______.

A．easy to find

B．easy to test

C．relatively cheap

D．smart in operation小题2:According to para.3, standing up while working ______.

A．tends to make us much healthier

B．get us distracted from the work at hand

C．can make us relaxed and be creative

D．make us move about and unfocused小题3:The underlined word “ unchained” in para.3 means “_______”

A．free

B．tired

C．uneasy

D．Unbalanced

男，42岁，慢性肾炎病史多年，近1年经常出现双下肢水肿，一直服潘生丁和氢氯噻嗪。近一周感觉腰痛，乏力，双下肢无力。首先必须考虑的是（）

A.肾功能严重减退

B.低钾血症

C.肾盂肾炎

D.潘生丁中毒

E.氢氯噻嗪中毒