水平位置盆栽的蚕豆幼苗，一段时间后根仍向下弯曲生长，茎向上弯

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问题单项选择题

水平位置盆栽的蚕豆幼苗，一段时间后根仍向下弯曲生长，茎向上弯曲生长。这是因为（）①重力影响，使生长素在靠近地面一侧浓度较高②光线影响，使生长素在靠近地面一侧浓度较高③根对生长素浓度的反应敏感④茎对生长素浓度的反应敏感

A.①②

B.②③

C.①③

D.②④

答案

参考答案：C

完形填空

One day a woman got into her car and started driving home after work. Suddenly, she saw a yellow car behind her. The 41 was a man. Wherever she drove, the young man followed her. When she 42 at the traffic lights, the yellow car stopped behind her.

The woman was afraid, so she drove 43 to the police station. She was very 44 when she found the car stopped behind her. At that time, she saw a woman outside the police station. She knew that she was a policewoman because she was wearing a police uniform. She jumped out 45 her car and ran to her. But the young man just smiled and came up to return the purse which was dropped on the street by the woman.

小题1: A. worker B. drover C. passenger

小题2: A. stop B. stops C. stopped

小题3: A. quickly B. easily C. happily

小题4: A. interested B. moved C. surprised

小题5: A. at B. on C. of

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填空题

一种以黄铜矿和硫磺为原料制取铜和其他产物的新工艺，原料的综合利用率较高。其主要流程如下：