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书面表达(15分)
假如你叫李明。你的好友Mark生病了,在家复习迎考。以下是学校关于英语期末考试的说明。请根据该通知写一封信给Mark,询问病情并告诉他考试的有关事宜。
| 期末考试时间:下周四上午8:00—10:00。 复习建议:掌握本学期所学的重要单词、短语及句型; 看笔记及平时的练习; 考前练习写几篇120字左右的作文。 如有疑难问题,请随时和老师或同学联系 |
2、字数:120词左右;
3、短文的开头与结尾已给出;
4、提示:短语:phrase 句型:sentence pattern
平时的练习:daily exercises 作文:composition
Dear Mark,
Sorry for your illness. Are you feeling any better now?
__________________________________________________________________________________________________________________________________________
Hope you will recover soon and also get a satisfactory mark in the exam.
Yours truly,
Li Ming 查看习题详情和答案>>
单词拼写 (本大题共10分,每小题1分)
(A) 根据句意,用括号内所给单词的适当形式填空。
1. There are two ________ (child) in my family.
2. The lovely room is the ________ (twin), not their parents’.
3. These newspapers are yours and those ones are ________ (we).
4. There are some ________ (America) coming to our school every year..
5. The supermarket isn’t closed now. It is ________ (closed).
(B) 根据句意和汉语注释,写出单词的正确形式。
6. ---How many ________ (堂兄弟) do you have? ---I have three.
7. The students in our school are all ________ and helpful (有礼貌的).
8. The boy in a white ________ ( 衬衫) is my cousin Andy.
9. The little children like to play ________ (模型) planes in the playground.
10. Jiangyin has many ________ (图书馆). Many people like to borrow books from them.
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根据对话内容从所给的选项中选出最佳答案,使对话完整,符合逻辑,句义通顺。注意:有多余选项。
A: You must be really excited about leaving for America tomorrow, Li Ping!
B: Yeah. 【小题1】______
A: Nervous about what?
B: I don’t know many of the customs and manners in the USA. 【小题2】______
A: Sure.
B: 【小题3】______
A: Well, it’s important to be on time when you’re invited for dinner. 【小题4】______ Americans expect their guests to be on time.
B: Then how long may I stay there?
A: 【小题5】______ Or you seem to have come only for the meal. When your friends seem to be getting tired and running out of things, it’s time to leave. The next day, call or write a thank-you note to say how much you enjoyed the evening.
| A.It’s good to stay at home for you. |
| B.After the meal, don’t leave at once. |
| C.Could you give me a hand? |
| D.What rules do they have in America? |
F. You’re supposed to leave before the meal.
G. It’s impolite to arrive late. 查看习题详情和答案>>
(A) 根据句意,用括号内所给单词的适当形式填空。
1. There are two ________ (child) in my family.
2. The lovely room is the ________ (twin), not their parents’.
3. These newspapers are yours and those ones are ________ (we).
4. There are some ________ (America) coming to our school every year..
5. The supermarket isn’t closed now. It is ________ (closed).
(B) 根据句意和汉语注释,写出单词的正确形式。
6. ---How many ________ (堂兄弟) do you have? ---I have three.
7. The students in our school are all ________ and helpful (有礼貌的).
8. The boy in a white ________ ( 衬衫) is my cousin Andy.
9. The little children like to play ________ (模型) planes in the playground.
10. Jiangyin has many ________ (图书馆). Many people like to borrow books from them. 查看习题详情和答案>>
一、制备K
二、提纯
方案1
方案2
主要试剂和产品的物理常数
| 名 称 | 相对分子质量 | 熔点或沸点(0C) | 水 | 醇 | 醚 |
| 水杨酸 | 138 | 158(熔点) | 微溶 | 易溶 | 易溶 |
| 醋酸酐 | 102 | 139.4(沸点) | 反应 | 可溶 | 易溶 |
| 乙酰水杨酸 | 180 | 135(熔点) | 微溶 | 可溶 | 微溶 |
(1)①合成阿斯匹林时,还会生成一些副产品,其中有一种是高分子,为了分离此物质,方案1中加入A物质为 ▲ 溶液。
②本方案抽滤后进行洗涤,其具体操作是 ▲ 。
(2)方案2为改进的提纯方法,称为重结晶提纯法。
①该方案中步骤1除了选用乙酸乙酯外,还可选择下列哪些
试剂 ▲ 。
A. 乙醇 B. 蒸馏水 C. 乙醚
②步骤2回流的装置如图所示,写出仪器a的名称 ▲ ,使用温度计的目的是 ▲ ,冷凝水的流向为 ▲ 。
③方案2所得产品的有机杂质要比方案1少的原因是 ▲ 。
(3)该学习小组在实验中原料用量:2.0g水杨酸、5.0ml醋酸酐(ρ=1.08g·cm-3),
最终称量产品m="2.2g" ,则乙酰水杨酸的产率为 ▲ 。 查看习题详情和答案>>