网址：http://m.1010jiajiao.com/timu_id_2268002[举报]
（1）若图甲是癌细胞的细胞膜，则膜上含量较正常细胞减少的物质是[ ] 。
（2）若图甲是线粒体膜，b和c过程运输的气体分别是 。b、c运输方式符合图 所表示的物质运输曲线。
（3）若图甲表示人体红细胞膜，则表示Na＋、K＋运输的分别是图中 。Na＋、K＋的运输方式符合图 所示曲线。
（4）已知红细胞吸收葡萄糖是协助扩散，而有人认为小肠上皮细胞以主动运输的方式吸收葡萄糖，请设计实验加以确定。
①实验步骤：
第一步：取甲、乙两组生理状况相同的小肠上皮细胞，放入适宜浓度的含有葡萄糖的培养液中。
第二步：甲组细胞给予正常的呼吸条件， 。
第三步： 。
②预测实验结果并分析：
a．若甲、乙两组细胞对葡萄糖的吸收速率基本相同，则 。
b． 。 查看习题详情和答案>>
实验一：将空白琼脂和含EDTA的琼脂做成帽状，分别套在甲、乙两组玉米胚根的根冠外（示意图如下）。提示：EDTA的作用是去除与其临接部位的 Ca2+。
将胚根水平放置培养一定时间后，观察到甲组胚根向重力（下）生长，乙组胚根水平生长。根据上述实验结果，得出实验结论： 。
实验二：水平放置的胚根弯曲向下生长，与根冠近地侧的Ca2+浓度明显高于远地侧有关。研究表明，根总是朝着Ca 2+浓度高的方向弯曲生长。为验证这一结论，有人设计了下列实验方案。请根据提供的实验材料和用具，写出第二步及以后的实验步骤和实验结果，并回答问题。
（1）实验材料和用具：胚根等长的萌发玉米种子，空白琼脂帽，含EDTA的琼脂帽，上面部分含Ca2+的琼脂帽（水平方向），培养皿等。
（2）实验步骤：
第一步：取若干个培养皿，在每个培养皿中放置适量的萌发玉米种子，按实验一中乙组的方法处理胚根一定时间后，移去根冠外的琼脂帽。然后将培养皿平均分成两组，编号为 A组、B 组。
第二步： 。
第三步： 。
（3）实验结果： 。
（4）科学家进一步证实，根冠中生长素的分布受Ca2+浓度影响，当胚根水平放置时，重力诱导Ca2+向根冠下侧移动，导致近地侧的生长素浓度比远地侧高。请分析胚根的生长素分布与向重力生长的关系： 。 查看习题详情和答案>>
阅读短文，在其后空白处写出各单词的正确形式。单词的第一个字母已经给出。
The worst traveler in the world was Paul of San Francisco. Once he f____1. from the U.S. to his hometown in Italy to see someone at home. The plane made a one-hour stop to get oil at an airport in New York. Paul thought he was in Rome. C____2., he got off the plane.
When nobody was there to meet him, Paul thought maybe the heavy t____3. made his friends late. While looking for their address, Paul found that the old “Rome”had changed a lot. He found many high m____4. buildings instead of old ones. He also found that many people spoke English but not Italian and that many street signs were w____ 5. in English.
Paul knew very l____6. English. So he asked a policeman in Italian the way to the bus station. He happened to meet a policeman who was also born in Italy and answered in the same l____7..
After twelve hours’ traveling round on a bus, the driver handed him over to a____8. policeman. But this time, this policeman could only speak English. So paul asked the policeman why the Rome police employed（雇佣）so many people who spoke English as policemen.
Paul didn’t b____9. he was in New York when he was told so. To get him on a plane to Italy, he was s____10. to the airport in a police car.
查看习题详情和答案>>
在下列给出的单词中，选出最适合的一个填写在横线上
go do have study play talk ride listen?
1. At three o'clock, we take a break and________ to some students.
2. The twins _______ to the cinema on Sunday evening.
3.On Saturday evening, Lingling and Kitty________ to music.
4. Daming and Tony ________ football on the playground on Saturday afternoon.
5. The pupils go home at four o'clock and ________ homework.
6. We don't_________ chemistry, art or history on Thursday afternoon.
7. The students _________ English at school.
8. We_______ to school every day. It is far(远).
查看习题详情和答案>>
补全对话(共5分)
从方框内选择恰当的句子完成下面的对话。(共5分，每小题1分)
|
A. A table for two? B. What can I do for you? C. My I take your order now? D. Excuse me. Could we have some coffee, please? E. This way, please. F. Anything else? G. What would you like to drink? |
Waiter: Good morning, madam.
Gina: Good morning.
Waiter: 1._____________
Gina: Yes. Can we have table by the window?
Waiter: OK. 2. _____________
( At the table )
Waiter: Here's the menu. 3.__________
Gina: Yes. We'd like chicken with potatoes, beef with onions and some rice.
Waiter: 4.__________
Gina: Orange juice.
Waiter: 5.________
Gina: No, that's all. Thank you.
查看习题详情和答案>>