问题 选择题

下列有关血液的叙述不正确的是(  )

A.人体血液由血浆、白细胞、红细胞和血小板组成

B.红细胞的特性是在一氧化碳浓度高的地方易跟氧气结合,在一氧化碳浓度低的地方易跟氧气分离

C.当人患急性炎症时,白细胞会较多地集中到炎症发生的部位

D.当人体血管破裂时,血小板会在伤口处聚集,从而达到止血的目的

答案

血液由血浆、血细胞两部分组成.血细胞包括红细胞、白细胞和血小板.血液的主要功能是运输功能、防御功能和调节体温的功能.红细胞数目最多,形态为双面凹的圆饼状,无细胞核,主要的功能是运送氧,和一部分二氧化碳;血红蛋白在一氧化碳浓度高的地方易跟氧气结合,在一氧化碳浓度低的地方也很难分离.白细胞:比红细胞大,有细胞核,吞食病菌,对人体有防御和保护作用;血小板:个体最小,性状不规则,无细胞核,有凝血和止血过的作用.

故选B.

填空题



Every human being is fallible; we make mistakes. In America when a mistake has been made, it is considered fitting for the person (1) to acknowledge his or her error and to apologize to anyone who has been inconvenienced. Even (2) are expected to admit their mistakes and apologize for them. Trying to (3) a mistake and denying your guilt are considered to be indicative of serious (4) .
If you make a mistake that (5) a group of people, a public apology is considered the best method for (6) . If the mistake was a serious one, or if some people were inconvenienced more than others, then the (7) should follow the public apology with private ones to (8) .
It is especially important for executives and company heads to be able to admit their mistakes. Sometimes leaders are afraid that if they (9) , they will lose the respect of their employees. Actually (10) — if you are honest with your employees and yourself, (11) , and show that you are willing to accept blame when you make a mistake, then your employees will be (12) you. They will also be more likely to admit their own mistakes.
If you (13) one person, it is usually best to apologize to that person alone, unless your mistake (14) by a large group of people. For example, if Leonard (15) to Mr. Todd during a committee meeting, it would be (16) for Leonard to apologize to Mr. Todd at the next committee meeting. If the (17) created by the initial mistake is public, then the apology should be public. However, if Leonard raised his voice to Mr. Todd when only the two of them (18) , he may apologize privately. Notice as well (19) the apologies are. As soon as you realize you have made a mistake, you should (20) .

单项选择题