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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>>
（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>>
这是一个单词纸牌游戏．请你在阅读完短文后，把A、B、C、D、E五个图片按游戏的正确步骤(Steps1－5)重新排列，然后完成下题．
This was one of my favourite games when I was a little girl. My sister and I used to play it for hours at a time. To play this game we made twenty-six small pieces of cards. On each of these cards we printed an English letter. And this is how we played it:
First, before we started to play, we decided what the game would be about. For example, we chose to play flowers.
One of us would then mix(混合) the cards and turn over the one on top of them. If the letter on the card happened(碰巧) to be P, we would try to think, as quickly as possible, of a flower which began with P, such as pansy(紫罗兰) or pink(石竹花). The one who first gave the name of the flower won that card. This was done with each of the twenty-six cards.
In the end the person who had more cards won the game.
Step 1．____ Step 2．____ Step 3．____ Step 4．____ Step 5．____
1．Which is RIGHT?
[ ]
A．The game can only be played between two people.
B．If you choose to play flowers, the letter on the card will be P.
C．The winner has to win every card of the game.
D．The one who loses the game doesn't think as quickly as the winner.
查看习题详情和答案>>听力部分
一．听对话，选择与对话内容相符的图片，将代表图片的字母填在相应的序号后。每段对话读两遍。(共5分，每小题1分)
1．________ 2．________ 3．________ 4．________ 5．________
二．听对话，根据对话内容，判断句子的正误。正确的写T，错误的写F。每段对话读两遍。(共5分，每小题1分)
听第一段对话，判断第6－7小题。
( )6．They need people for the basketball team．
( )7．Richard has been playing basketball for five years．
听第二段对话，判断第8－10小题。
( )8．Sunny has never been to the Beijing Aquarium．
( )9．They will ride their bikes to go there．
( )10．Joe has been to the zoo only once．
三．听对话，根据对话内容，从下列各题所给的A、B、C三个选项中，选择最佳选项。对话读两遍。(共5分，每小题1分)
听对话，回答第11－15小题。
11．What is Ben going to do today?
A．To fly a kite．
B．To pick up the shells．
C．To visit the aquarium．
12．How old was Ben when he started collecting kites?
A．Thirty years old．
B．Thirteen years old．
C．Ten years old．
13．Why does Ben like to collect shells?
A．They are cheap．
B．It is difficult to find them．
C．They are beautiful and easy to get．
14．How many shells has Ben been collecting?
A．About 300．
B．About 130．
C．About 113．
15．Where are they talking probably?
A．In the park．
B．At the bus stop．
C．In the aquarium．
四．听短文，根据短文内容，完成下面的表格。短文读三遍。(共5分，每小题1分)
听力部分(25分)
Ⅰ．情景反应 根据你所听到的句子，选择恰当的应答语。5’(1’×5)
1．
A．Six years ago．
B．In six years．
C．For six years．
2．
A．I like it, too．
B．Since 2010．
C．Yes, I really do．
3．
A．Great．
B．No, not at all．
C．Yes, I do．
4．
A．Yes, I could．
B．Sure．
C．You’re welcome．
5．
A．I have a headache．
B．Yes, it is．
C．Good idea．
Ⅱ．对话问答 根据你所听到的对话及问题，选择正确答案。5’(1’×5)
6．
A．For 6 years．
B．For 10 years．
C．For 16 years．
7．
A．Since she was seven years old．
B．For seven years．
C．For seven months．
8．
A．Turn down the music．
B．Get up．
C．Get out of the bathroom．
9．
A．Leave the yard．
B．Clean the yard
C．Leave school．
10．
A．A waitress．
B．A store clerk．
C．A barber．
Ⅲ．图片理解 看图听描述，选择与你听到内容相符的选项。其中有一幅是多余的5’(1’×5)
11．________
12．________
13．________
14．________
15．________
Ⅳ．听较长对话，选择正确答案。5’(1’×5)
听第一段对话，作答16-17小题
16．Who will have a party?
A．Jenny．
B．Mike．
C．Jenny and Mike．
17．When will the party start?
A．At 1 pm．
B．At 2 pm．
C．At 3 pm．
听第二段对话，作答18-20小题
18．What is Bob doing?
A．Talking with a boy．
B．Reading a story．
C．Making a robot．
19．What can Jim do?
A．Clean the rooms．
B．Play the guitar．
C．Play sports games．
20．Who is Ann?
A．A dog．
B．A robot．
C．A girl．
V．短文理解 根据短文内容，选择正确答案。5’(1’×5)
21．Liam ordered ________ from Nick's store．
A．a watch
B．a computer
C．a camera
22．The store clerk said “ ________ ” on the phone．
A．I am sorry．
B．Excuse me．
C．Can I help you?
23．Liam will give the present to him ________．
A．on Nick's birthday
B．on his uncle's birthday
C．on his father's birthday
24．His uncle is ________．
A．14 years old
B．50 years old
C．40 years old
25．Liam ________ the camera．
A．bought
B．doesn't want to buy
C．has bought