题干

下列科学发现与研究方法相一致的是(    )

①1866年孟德尔的豌豆杂交实验,提出遗传定律

②1903年萨顿研究蝗虫的减数分裂,提出假说“基因在染色体上”

③1910年摩尔根进行果蝇杂交实验,证明基因位于染色体上

④科学家获得不同形态的细胞器

⑤研究分泌蛋白的形成过程.

A:①假说﹣演绎法  ②类比推理法  ③类比推理法  ④差速离心法  ⑤对比实验法

B:①假说﹣演绎法  ②类比推理法  ③假说﹣演绎法  ④差速离心法  ⑤同位素标记法

C:①假说﹣演绎法  ②假说﹣演绎法  ③假说﹣演绎法  ④离心  ⑤对比实验法

D:①类比推理法  ②假说﹣演绎法  ③类比推理法  ④对比分析法  ⑤同位素标记法

上一题 下一题 0.0难度 选择题 更新时间:2018-06-05 09:43:49

答案(点此获取答案解析)

B

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阅读理解

    Quietly sitting there reading, I found myself suddenly listening to the train guard's announcements. Train travelers will surely agree that when the guard makes an announcement, whether it's the recorded message or the guard's message, few people listen to it, because it's often quite dull or hard to understand. This one was different. I noticed that other passengers appeared to be listening, too. Not only that, everyone was smiling!

    Why was so much attention being paid to this message? As best I can recall, the guard said something along these lines, “Good Morning Ladies, Gentlemen and Children, this is the 7:35 a.m. from Penrith to Central and you'll be pleased to know that we are right on time. And what a lovely morning it is in Sydney today. The sun is shining, birds are singing, and all's right with the world. I trust you have a great day wherever you're going. Thanks for catching my train this morning and I hope to see you again soon.”

    Quite a few people (obviously previous strangers) started talking to one another about the guard's excellent message and how good it had made everyone feel. I started thinking about this, and then I found the young guard and said “Were you the guard on the 7:35 a.m. from Penrith?” The guard seemed a bit stunned at first, replying, “Yes, yyyyes.” “Well, I really appreciate your announcement. Thank you for your extremely good message, which gave me and the other passengers such a good start to the day. Please keep doing it.” I said.

    There are two messages for me in what happened that day. Firstly, when people are happy in their work it shows in what they do and say. Secondly, the story attaches much importance to the benefits that accumulate from thanking people for something they've done, particularly when it's not expected. Can you imagine the conversation that guard would have when he got home?