9. Why does the man think he was lucky to get the job in a little village?

　 A. He likes quiet places.　　　 B. He likes the factory.　　　 C. He likes the job.

8. What can we learn from the conversation?

　 A. A factory was built to clean the town.

　 B. A big factory is being built to deal with the rubbish.

　 C. Another factory will be set up in town to produce rubbish.

请听第7段材料，回答第9至第11题

7. How much rubbish can the factory deal with each day?

　 A. 300 tons　　　　　 B. 3,000 tons　　　 C. 30,000 tons

6. Where is the factory mentioned in the conversation?

　 A. Near the town　　　　 B. Far from the town　　　 C. North of the town

4. How many turns does the woman have to take?

　 A. Two　　　　　　 B. Three　　　　　 C . Four

3. What is the man used to?

　 A. To wearing hat.　　 B. To being done harm to　 C. To going out without covering his head

2. Why was Carl Johnson at the hospital?

　 A. He is sick.　　　 B. His wife just had a baby.　　　 C. He was visiting his daughter.

48．(18分)甘薯和马铃薯都富含淀粉，但甘薯吃起来比马铃薯甜，为探究其原因，某兴趣小组以甘薯的块根和马铃薯的块茎为材料，在不同温度、其他条件相同的情况下处理30 min后，测定甘薯块根还原糖含量见下表，而马铃薯块茎不含有还原糖。

(1)由表可见，温度为70 ℃时甘薯还原糖含量最高，这是因为_________________。

(2)请你推测马铃薯块茎不含有还原糖的最可能原因是_________________________。

(3)为了确认马铃薯不含还原糖的原因，请完成以下实验：

实验原理：①____________________________________________；

②____________________________________________。

备选材料与用具：甘薯提取液(去淀粉和还原糖)，马铃薯提取液(去淀粉)，1%醋酸洋红溶液，本尼迪特试剂，双缩脲试剂，质量分数为3%的淀粉溶液和质量分数为3%的蔗糖溶液等。

实验步骤：

第一步：取A、B两支试管，在A管中加入甘薯提取液，B管中加入等量的马铃薯提取液。

第二步：70℃水浴保温5 min后，在A、B两支试管中各加入___________________。

第三步：70℃水浴保温5 min后，在A、B两支试管中再各加入_________________。

第四步：______________________________________。

实验现象：____________________________________。

实验结论：____________________________________。