题干

小明在显微镜下看到了下面的血管图,结合血液流动的局部模式图,回答以下问题.

(1)在显微镜下辨别三种血管的理由是:动脉内的血液由较____ (填“粗”或“细”)的血管流向较____ (填“粗”或“细”)而分支____ (填“多”或“少”)的血管;

(2)静脉内的血液是由较____ (填“粗”或“细”)而分支____ (填“多”

或“少”)的血管汇流入较____ (填“粗”或“细”)的血管;

(3)毛细血管内血液中的红细胞一般成____ 通过,血流速度____ ,该血管的结构特点是管壁由____ ,构成的.最慢

(4)由此可判断①是____ 血管,②是____ 血管,③是____ 血管

(5)若①②③为对应血管中血流速度,则血液流速关系表述为____ (请用图中的序号和“>”表示)

上一题 下一题 0.0难度 选择题 更新时间:2016-11-11 05:24:07

答案(点此获取答案解析)

粗,细,多,细,少,粗,单行,最慢,一层上皮细胞,动脉,毛细,静脉,①>③>②

同类题4

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

    What do the world's most successful people all have in common?

By examining the work habits of over 150 greatest writers and artists and scientists, the researchers including Stanford professor Jeffrey Pfeiffer found that high achievers like Robert Moses turned out to be all alike: 

Busy! Busy!

    ____ In a study of general managers in industry, John Kotter reports that many of them work 60 to 65 hours per week—which translates into at least six 10-hour days. The ability and willingness to work difficult and tiring hours has characterized many powerful figures. Energy and strength provide many advantages to those seeking to build power.

Just Say No!

    The difference between successful people and very successful people is that very successful people say “no” to almost everything. And that's what gives them the time to accomplish so much.____ And focus means saying “no” to a lot of distractions (分神).

____

    Ignore your weaknesses and keep improving your strengths. Don't waste time exploring skill areas where you have little competence. Instead, focus on—and build on—your strengths. This means knowing who you are, what you are and what you are good at.

Create Good Luck!

    ____ There's a science to it. Richard Wiseman studies lucky people for his book Luck Factor, and breaks down what they do right. Certain personality types are luckier because they behave in a way that offers the chance for good opportunities. By being more outgoing, open to new ideas, following the feeling that something is true, and being optimistic, lucky people create possibilities.

    Does applying these principles to your life actually work? Wiseman created a “luck school” to test the ideas—and it was a success. In total, 80 percent of the people who attended Luck School said that their luck had increased.____

A. Spend enough time to improve your weakness.

B. Achievement requires focus.

C. On average, these people reported that their luck had increased by more than 40 percent.

D. They never stop working and they never lose a minute.

E. Busy people are more likely to be lucky.

F. Know What You Are!

G. Luck isn't magical.