题干

将三种植物根细胞放在不同浓度盐溶液中,一段时间后观察质壁分离百分比,结果如表所示.下列说法正确的是(  )

浓度
植物种类

盐溶液浓度(g/L)及质壁分离百分比(%)

3

4

5

6

7

8

9

0

27

58

82

100

100

91

0

0

0

0

0

54

88

0

0

0

23

52

68

100

A:三种根细胞的原生质层由细胞膜和液泡膜构成

B:高浓度盐溶液会导致细胞死亡而失去选择透过性

C:实验结束后9g/L溶液中的水不能进出丙细胞

D:乙的细胞液浓度最小,最适宜在盐碱地生长

上一题 下一题 0.0难度 选择题 更新时间:2020-01-05 12:11:59

答案(点此获取答案解析)

B

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    My first full time job after high school was selling vacation packages via telephone for a well-known company. One day, the dialer 1me to a man who answered the phone and2a bit out of breath. I started with my normal pitch(推销), and3to hear the normal, "I don't want any," and be hung up on.

    Instead he spoke in a low, weak voice and told me how he wished he could take a4like the one I was offering, but couldn't5he was dying of emphysema (肺气肿). He 6how he was on oxygen, and it took almost all his7just to get to the phone to answer the call. I8 and my heart fell into my stomach. He asked me if I smoked, which I did, and then begged me to stop. He told me smoking is 9was killing him, and how horrible it was. He told me to 10every day with my loved ones, and tell them all the time how much I love them. At this 11, I was in tears, and couldn't control myself, and he could tell.

    After a few moments, I decided to write down his name and 12, and just send him a card telling him that I13his advice and that I would pray for him and his family. Shortly after, I received a nice letter back from Frank, along with a picture of him and his wife. We continued to write back and forth over the next few months or so, and became very 14of each other. He was old enough to be my grandfather, and in many ways, I felt 15he were.

    It was about a year later I received a letter from his wife, and when I started to read it, my eyes were filled with tears. She told me how Frank's 16with the disease had finally come to an end, and he 17shortly before Christmas .She wanted to thank me for the letters I had written to Frank, and then explained how Frank touched many lives over the years. At his 18  to show just that, they read the 1st letter I had written to Frank to show how he 19a 19-year- old person he had20even met.

    I will never forget how much that meant to me.