题干

将酶、抗体、核酸等生物大分子或小分子药物用磷脂制成的微球体包裹后,更容易运输到患病部位的细胞中,这是因为                                                                                     (   )

A:生物膜具有选择透过性,能够允许对细胞有益的物质进入

B:磷脂双分子层是生物膜的基本支架,且具有一定的流动性

C:微球体能将生物大分子药物水解成小分子药物

D:生物膜具有半透性,优先让生物大分子物质通过

上一题 下一题 0.0难度 选择题 更新时间:2019-08-07 07:10:41

答案(点此获取答案解析)

B

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任务型阅读
   请阅读下面短文,并根据所读内容在文章后表格中的空格里填入一个最恰当的单词。
   注意: 请将答案写在答题卡上相应题号的横线上。 每个空格只填一个单词。
           People select news in expectation of a reward. This reward may be either of two kinds. One is related to what Freud calls the Pleasure Principle, the other to what he calls the Reality Principle. For want of better names, we shall call these two classes immediate reward and delayed reward.
           In general, the kind of news which may be expected to give immediate reward are news of crime and corruption, accidents and disasters, sports, social events, and human interest. Delayed reward may be expected from news of public affairs, economic matters, social problems, science, education, and health.
           News of the first kind pays its rewards at once. A reader can enjoy an indirect experience without any of the dangers or stresses involved. He can tremble wildly at an axe-murder, shake his head sympathetically and safely at a hurricane, identify himself with the winning team, laugh understandingly at a warm little story of children or dogs.
           News of the second kind, however, pays its rewards later. It sometimes requires the reader to tolerate unpleasantness or annoyance — as, for example, when he reads of the threatening foreign situation, the mounting national debt, rising taxes, falling market, scarce housing, and cancer. It has a kind of “threat value.” It is read so that the reader may be informed and prepared. When a reader selects delayed reward news, he pulls himself into the world of surrounding reality to which he can adapt himself only by hard work. When he selects news of the other kind, he usually withdraws from the world of threatening reality toward the dream world.
           For any individual, of course, the boundaries of these two classes are not stable. For example, a sociologist may read news of crime as a social problem, rather than for its immediate reward. A coach may read a sports story for its threat value: he may have to play that team next week. A politician may read an account of his latest successful public meeting, not for its delayed reward, but very much as his wife reads an account of a party. In any given story of corruption or disaster, a thoughtful reader may receive not only the immediate reward of indirect experience, but also the delayed reward of information and preparedness. Therefore, while the division of categories holds in general, an individual’s tendency may transfer any story from one kind of reading to another, or divide the experience between the two kinds of reward.
What news stories do you read?
Division of
news stories
● People expect to get ____ from reading news.
● News stories are roughly divided into two classes.
● Some news will excite their readers instantly while others won’t.
____ of
the two classes
● News of immediate reward will seemingly take their readers to the very frightening scene without actual ____  .
● Readers will associate themselves closely with what happens in the news stories and____ imilar feelings with those involved.
●  News of delayed reward will make readers suffer, or present a____ to them.
●  News of delayed reward will induce the reader to____ for the reality while news of immediate reward will lead the reader to ____ from the reality.
Unstable boundaries
of the two classes
●  What readers expect from news stories are largely shaped by their ____ .
●  Serious readers will both get excited over what happens in some news stories and ____  themselves to the reality.
●  Thus, the division, on the whole,____ on the reader.