题目

焰色反应属于（  ） A.元素的性质                                                 B.单质的性质 C.离子的性质                                                 D.化合物的性质 答案：A 解析:焰色反应是金属或金属化合物的离子在灼烧时表现出来的性质，是金属元素的性质，是一种物理现象，而不是化学性质，B、C、D三个选项都不全面。Do you still get free plastic bags from the supermarkets? Things have changed.China has banned（禁止）free plastic bags at shops and supermarkets, and people have to pay for using plastic bags. The rule started on June 1.It came because our country tried to make litter less. Making super-thin（超薄）plastic bags has also been banned.The Chinese once used about 3,000,000,000 plastic shopping bags a day, and they have caused pollution of the environment. The bags have become a main cause of plastic pollution because they are easy to break and people throw them away here and there .So the Chinese people are encouraged to bring their own bag for shopping.What kind of shopping bag is the best to bring? Some students in Chongqing have a good idea. They make their own shopping bags. They use old clothes to make cloth bags（布袋）. And send them to their parents as presents. They also ask their parents and friends to use cloth bags instead of plastic ones. They think it is their duty to protect the environment.【1】People in China have to ______now.A. throw plastic bags here and thereB. use free plastic bagsC. pay for using plastic bags at shops and supermarkets【2】China made this rule because plastic bags were bad for the ____.A. environment B. litter C. shops【3】The Chinese people are encouraged to bring ______ for shopping.A. super-thin plastic bagsB. free plastic bagsC. their own bags【4】Some students in Chongqing________.A. ask their parents to make cloth bagsB. make cloth bags themselvesC. buy cloth bags for their parents【5】What’s the main idea of this article（文章）?A. Making super-thin plastic bags has been banned in China.B. The bags have become a main cause of plastic pollution.C. To protect the environment, free plastic bags have been banned in China.