答案：　C

　　2．One of the purposes of DustCart's asking for the user's ID number was to________.

　　A．charge the person automatically

　　B．follow the moving path of the garbage

　　C．record the family's monthly amount of trash

　　D．get the person's comment on the service later

　　解析：　细节理解题。根据第四段中Once the robot arrived，it asked for a personal ID number that both identifies the user and tracks the garbage可知，留下垃圾投放人的ID号码目的之一是为了可以追踪其扔掉的垃圾。

　　答案：　B

　　3．Compared with traditional trash collection，DustCart________.

　　A．reduces the cost greatly

　　B．makes much less noise

　　C．works better in trash recycling

　　D．can work in the middle of night

　　解析：　细节理解题。根据第五段中Dario，the head scientist，said DustCart could also be an answer to the noise pollution that comes with traditional trash collection in Italy可知，与传统垃圾回收方式相比，DustCart能够降低噪音。

　　答案：　B

　　4．It can be inferred from the passage that________.

　　A．the dumping site is causing serious pollution

　　B．there are not enough garbage men in Italy

　　C．DustCart will not come into use very soon

　　D．traditional trash collection causes traffic problems

　　解析：　推理判断题。根据第七段可推知，DustCart还存在一些不足有待改进，故其真正投入使用还有待时日。

　　答案：　C

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