问题 选择题

人在大量出汗或严重腹泻的情况下,血液中主要丢失了什么成分(  )

A.血浆

B.红细胞

C.白细胞

D.血小板

答案

(1)试管中放置一些新鲜的动物血液,加入抗凝剂(或柠檬酸钠),防止血液凝固,由于重力的不同而出现分层现象,血液由血浆和血细胞组成,血细胞包括红细胞、白细胞和血小板,如图:

血浆的主要作用是运载血细胞,运输维持人体生命活动所需的物质和体内产生的废物等.血浆相当于结缔组织的细胞间质,是血液的重要组成分,呈淡黄色液体(因含有胆红素).血浆的化学成分中,水分占90~92%,人在大量出汗或严重腹泻的情况下,主要散失的水水分,所以血液中主要丢失的是血浆.

故选:A

阅读理解

阅读理解

We are just getting older and older with each New Year. Vigor and wisdom are draining, and bit by bit we are moving away from the amazement of youth.

Yet neither fear nor anxiety helps retain youth. Instead, a few living habits help maintain.

●Laugh to your heart's content as much as you can. Laughter helps reduce pressure and improve your immune system, which makes people look 8 years younger.

●Keep an eye on your blood pressure. Those with a blood pressure of 115/75mmHg look 2.5years younger than those above 160/90mmHg.

●Quit smoking and avoid passive smoking. This can take 8 years off your appearance.

●Spare some time for exercises each day. Exercises need not be tiring. A 20 minute walk every day makes people look 5 years younger.

●Keep learning and absorb something new each day. Speak the same language as the young people. Learning something every day makes people look 2.5 years younger.

●Keep other pressures under control. Too much pressure makes people look 30 years older. If they are good at networking and manage to keep pressure under control, they will look 30 years younger.

●Secure high quality medical care insurance and do whole body check regularly. For those contracted with chronicle diseases, proper treatment and qualification of the diseases makes people look 12 years younger than what they would without proper treatment.

小题1:The passage is mainly about _________.

A.the important of retaining youth

B.some tips helping people retain youth

C.moving away from the amazement of youth

D.the connections between the health and the age小题2:The underlined sentence “This can take 8 years off your appearance.” means _________.

A.Smoking and passive smoking can make you look 8 years younger

B.Smoking and passive smoking can make you die 8 years ahead

C.Giving up smoking and avoiding passive smoking can make you live 8 years longer

D.Giving up smoking and avoiding passive smoking can make you look 8 years younger小题3:According to the passage, we can know that _________.

A.exercises properly every day helps people retain youth

B.if you want to be 30 years younger you must keep other pressures under control

C.doing whole body check regularly can make people look younger

D.fear and anxiety are a part of our life, which help people realize the importance of keeping youth

多项选择题