《2022年考博英语-西南财经大学考前模拟强化练习题49（附答案详解）》由会员分享，可在线阅读，更多相关《2022年考博英语-西南财经大学考前模拟强化练习题49（附答案详解）（21页珍藏版）》请在金锄头文库上搜索。
1、2022年考博英语-西南财经大学考前模拟强化练习题（附答案详解）1. 单选题Blood vessels running all through the lungs carry blood to each air sac（囊）, or alveolus（肺泡）, and then back again to the heart. Only the thin wall of the air sac and the thin wall of a capillary（毛细血管）are between the air and the blood. So oxygen easily diffuses fr
2、om the air sacs through the walls into the blood, while carbon dioxide easily diffuses from the blood through the walls into the air sacs.When blood is sent to the lungs by the heart, it has come back from the cells in the rest of the body. So the blood that goes into the wall of an air sac contains
3、 much dissolved carbon dioxide but very little oxygen. At the same time, the air that goes into the air sac contains much oxygen but very little carbon dioxide. You have learned that dissolved materials always diffuse from where there is more of them to where there is less. Oxygen from the air disso
4、lves in the moisture on the lining of the air sac and diffuses through the lining into the blood. Meanwhile, carbon dioxide diffuses from the blood into the air sac. The blood then flows from the lungs back to the heart, which sends it out to all other parts of the body.Soon after air goes into an a
5、ir sac, it gives up some of its oxygen and takes in some carbon dioxide from the blood. To keep diffusion going as it should, this carbon dioxide must be gotten rid of. Breathing, which is caused by movements of the chest, forces the used air out of the air sacs in your lungs and brings in fresh air
6、. The breathing muscles are controlled automatically so that you breathe at the proper rote to keep your air sacs supplied with fresh air. Ordinarily, you breathe about twenty-two times a minute. Of course, you breathe faster when you are exercising and slower when you are resting. Fresh air is brou
7、ght into your lungs when you breathe in, or inhale（吸入）, while used air is forced out of your lungs when you breathe out, or exhale.Some people think that all the oxygen is taken out of the air in the lungs and that what we breathe out is pure carbon dioxide. But these ideas are not correct. Air is a
8、 mixture of gases that is mostly nitrogen（氮）. This gas is not used in the body. So the amount of nitrogen does not change as air is breathed in and out. But while air is in the lungs, it is changed in three ways: (1) About one fifth of the oxygen in the air goes into the blood. (2) An almost equal a
9、mount of carbon dioxide comes out of the blood into the air. (3) Moisture from the linings of the air passages and air sacs evaporates until the air is almost saturated.1.It can be inferred from the passage that oxygen and carbon dioxide（ ）.2.When blood travels back to the lungs by the heart,（ ）.3.T
10、he movement of breathing can effectively（ ）.4.When we breathe out, the amount of nitrogen（ ）.5.The air in the lungs changes through（ ）.问题1选项A.produce energy for breathingB.diffuse immediately in the bloodC.penetrate slowly into the air sacsD.travel in opposite ways in the lungs问题2选项A.more oxygen was
11、 contained in bloodB.more carbon dioxide was contained in the bloodC.less carbon dioxide was contained in an air sacD.less oxygen was contained in an air sac问题3选项A.help the exchange of oxygen and carbon dioxide in the lungsB.prevent the inhaling of excessive carbon dioxideC.keep the regular circulat
12、ion of bloodD.strengthen the function of breathing muscles问题4选项A.increases a bit because of the exchange of airB.reduces a bit because of the exchange of airC.remains the same as we breathe it inD.keeps the same as that needed in lungs问题5选项A.inhaling some amount of oxygenB.the evaporation of moistur
13、eC.exhaling some amount of carbon dioxideD.generating a passage for evaporation【答案】第1题:D第2题:B第3题:A第4题:C第5题:B【解析】第1题:推理判断题。文章提到气囊中二氧化碳过多会迫使人进行呼吸，而不是说它们为呼吸产生能力，因此选项A可以排除；文章第一段最后一句话的后半部分提到“二氧化碳很容易从血液中扩散到气囊中”（while carbon dioxide easily diffuses from the blood through the walls into the air sacs），由此可知二氧
14、化碳是扩散到气囊而不是到血液中，所有选项B可以排除；文章第一段最后一句话的前半部分提到“所以氧气可以很轻易地通过气囊壁从气囊扩散到血液中”（so oxygen easily diffuses from the air sacs through the walls into the blood），所以选项C“它们都是很慢地渗透到气囊中”说法错误，排除。因此，选项D符合题意。第2题:细节事实题。文章第二段第一句话提到“当血液被心脏送到肺里的时候，它是从身上其他细胞里流回来的，所以流入气囊壁的血液带有很多溶解的二氧化碳和少量的空气”（When blood is sent to the lungs b
15、y the heart, it has come back from the cells in the rest of the body. So the blood that goes into the wall of an air sac contains much dissolved carbon dioxide but very little oxygen），所以这个时候血液里的二氧化碳含量会增加，选项B符合题意。第3题:细节事实题。文章第三段提到“由胸部的运动而产生的呼吸，促进了废气从气囊中排除，为肺部带来新鲜的空气”（Breathing, which is caused by mov
16、ements of the chest, forces the used air out of the air sacs in your lungs and brings in fresh air. The breathing muscles are controlled automatically so that you breathe at the proper rote to keep your air sacs supplied with fresh air），选项A“帮助肺部的氧气和二氧化碳进行交换”符合题意。第4题:细节事实题。文章第四段提到“空气是气体混合而成,其中氮气含量最高，这种气体我们人体不需要，所
