问题 单项选择题

下列关于人类生殖和发育的叙述错误的是()。

A.受精和胚胎发育的场所分别是输卵管和子宫。

B.男女第二性征的出现是性激素作用的结果。

C.提倡母乳喂养是因为母乳中不仅有婴儿所需要的营养成分还有抵抗传染病的抗体。

D.胎儿通过自身的呼吸系统和消化系统从母体获得氧气和营养成分。

答案

参考答案:D

解析:

胎儿在母腹中是不用“呼吸”的,他所需要的氧气和营养成分是通过母体与胎儿之间的脐带输送的。

单项选择题
阅读理解

Science can’t explain the power of pets, but many studies have shown that the company of pets can help lower blood pressure and raise chances of recovering from a heart attack, reduce loneliness and spread all-round good cheer.

Any owner will tell you how much joy a pet brings. For some, an animal provides more comfort than a husband/wife. A 2002 study by Karen Allen of the State University of New York measured stress (紧张) levels and blood pressure in people ---half of them pet owners ---while they performed 5 minutes of mental arithmetic (算术) or held a hand in ice water. Subjects completed the tasks alone, with a husband/wife, a close friend or with a pet. People with pets did it best. Those tested with their animal friends had smaller change in blood pressure and returned most quickly to baseline heart rates. With pets in the room, people also made fewer math mistakes than when doing in front of other companions. It seems people feel more relaxed (放松)around pets, says Allen, who thinks it may be because pets don’t judge.

A study reported last fall suggests that having a pet dog not only raises your spirits but may also have an effect on your eating habits. Researchers at Northwestern Memorial Hospital spent a year studying 36 fat people and their equally fat dogs on diet-and-exercise programs; a separate group of 56 people without pets were put on a diet program. On average, people lost about I1 pounds, or 5% of their body weight. Their dogs did even better, losing an average of 12 pounds, more than 15% of their body weight. Dog owners didn’t lose any more weight than those without dogs but, say researchers, got more exercise overall---mostly with their dogs --- and found it worth doing.

小题1:What does the text mainly discuss?

A.What pets bring to their owners.

B.How pets help people calm down.

C.People’s opinions of keeping pets.

D.Pet’s value in medical research.小题2:We learn from the text that a person with heart disease has a better chance of getting well if _____.

A.he has a pet companion

B.he has less stress of work

C.he often does mental arithmetic

D.he is taken care of by his family小题3:According to Allen, why did the people do better with pets around when facing stressful tasks?

A.They have lower blood pressure.

B.They become more patient.

C.They are less nervous.

D.They are in higher spirits.