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　　Dear Roni,

　　Italy is wonderful. We started in Rome two weeks ago, drove to Florence last week and now we're on our way to Venice. Three weeks just isn't enough.

　　The country near Florence is so beautiful－hills, olive trees. And red roofs(屋顶) of the houses look so nice far away.

　　I am afraid I am getting bigger－the food here is so delicious!

Love,

Akemi

　　Roni Lebaver

　　222 Main St. Languna

　　Beach, CA 92651

　　U. S. A.

　　Hi Roni,

　　I can't believe(相信) you went to school here in Honolulu! Why did you leave?

　　I spend each morning on the beach(海滩) and in the water. The sand is so soft and the beaches seem so long. The water is just the right temperature.

　　One afternoon, I left the beach to walk in mountains near Honolulu. I enjoyed myself very much there.

　　How I miss you!

Mari

　　Roni Lebaver

　　222 Main St. Languna

　　Beach, CA 92651

　　U. S. A.

　　Dear Roni,

　　Maybe I'm strange but I love the desert(沙漠)!

　　Last week, our group spent four days in the desert. At times, it felt like the moon.

　　I always thought deserts were all the same! They are not. Some parts look like mountains; others are really different.

　　And when we find something green－－a few plam trees, a little water, we feel good and great.

　　See you in September,

Kim

　　Roni Lebaver

　　222 Main St. Languna

　　Beach, CA 92651

　　U. S. A.

1．Who seems to have eaten too much?

[　　]

2．Who went to school in Honolulu?

[　　]

3．Who spent four days on the moon?

[　　]

4．Where does Roni live?

[　　]

5．Which of the sentences is true?

[　　]

A．Akemi arrived in Rome two weeks ago.

B．Mari spends every morning and afternoon on the beach.

C．Deserts always look the same.

D．Mari had a good time in Honolulu.

找出适当的字母或字母组合，使所给单词完整与正确。

______ke

[    ]

　　A. ca   B. cai   C. han   D. an

（10分）植物具有向重力生长的特性，下列是研究根向重力生长机理的两个实验。
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：                                  。

选择正确选项，完成所给单词.

ac __ __ dent

[　　]

A．si

B．ci

C．sa

D．ca