训练1
体裁：应用文
主题：化学实验
难度：★★★★
跨学科·化学 Do - it - yourself crystal(晶体)
You can grow crystals using bicarbonate of soda(小苏打). The experiment shows you how.

What’s happening?
Bicarbonate of soda is usually sold as a powder(粉末)made up of tiny crystals. The powder dissolves in water, which means the powder becomes mixed with water and disappears. The mixture of water and soda is soaked up(浸透)by the wool tied the jars together. The water then evaporates(蒸发)slowly, leaving behind pure bicarbonate of soda—which reforms into big crystals.
1. In this experiment, you may need some containers(容器)like .
① two jars
② a plate
③ a piece of wool
④ a paperclip
A. ①③
B. ②④
C. ①②
D. ③④
2. Both the ends of the wool are placed in each jar so as to the mixture.
A. soak up
B. leave behind
C. cool down
D. hang down
3. The underlined word “dissolves” in the last paragraph means “” in Chinese.
A. 溶解
B. 浸没
C. 解决
D. 凝结
4. According to the experiment, the following statement “” is TRUE.
A. Only six teaspoons of bicarbonate of soda are needed.
B. Two jars should be put in a cool place with a plate between them.
C. Leave the jars for at least seven days, and then you may see the crystals.
D. No crystals may hang down over the plate because they have disappeared.

1. C 细节理解题。根据“Fill two jars with hot water.”和“Put the jars in a warm place with a plate between them.”可知，做实验需要两个罐子和一个盘子。故选C。
2. A 细节理解题。根据“The mixture of water and soda is soaked up by the wool tied the jars together.”可知，毛线是为了吸收水和苏打的混合物。故选A。
3. A 词义猜测题。根据“The powder dissolves in water, which means the powder becomes mixed with water and disappears.”和常识可知，粉末放进水里会被溶解。故选A。
4. C 细节理解题。根据“Leave the jars for at least a week. Crystals should grow gradually along the wool, and hang them down over the plate.”可知，把罐子至少放一周以后，你就会看到晶体。故选C。

【分析】本题是跨学科英语阅读理解题，需结合实验步骤和文章内容，针对每个问题回到原文定位关键信息：第1题找实验所需容器，对应步骤1和2的描述；第2题考查毛线两端放罐的目的，对应文章中关于毛线作用的句子；第3题猜测“dissolves”的词义，结合上下文和常识；第4题判断正确陈述，需逐一核对选项与原文细节是否一致。
【解析】
1. 第1题：根据实验步骤1“Fill two jars with hot water.”和步骤2“Put the jars in a warm place with a plate between them.”可知，实验需要两个罐子和一个盘子，对应①②，故选C。
2. 第2题：根据文章中“The mixture of water and soda is soaked up by the wool tied the jars together.”可知，毛线两端放罐中是为了吸收水和苏打的混合物，“soak up”意为吸收，故选A。
3. 第3题：根据后文“the powder becomes mixed with water and disappears”及常识，粉末放入水中混合消失是“溶解”的意思，故选A。
4. 第4题：逐一核对选项：A项原文是“Spoon about six teaspoons”（约六勺），并非只需要六勺，错误；B项原文是“warm place”（温暖的地方），不是cool place，错误；C项原文“Leave the jars for at least a week”（至少一周，即七天），正确；D项原文说晶体会挂在盘子上，并非消失，错误，故选C。
【答案】1.C 2.A 3.A 4.C
【知识点】英语阅读理解、细节理解、词义猜测
【点评】本题结合化学实验的英语阅读，考查学生提取原文细节、猜测词义的能力，需仔细比对原文与选项的细节，注意修饰词（如“about”“warm”等），避免因粗心出错，整体难度适中。
【难度系数】0.7