题目

已知a、b、c在数轴上的位置如图，下列说法：①abc>0；②c+a>0；③c–b<0；④ >0．正确的有（ ） A . 1个 B . 2个 C . 3个 D . 4个 答案：C阅读理解。     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 (环境污染). 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 bags for shopping.     What kind of shopping bag is the best to bring? Some students in Chongqing have a good idea. They maketheir own shopping bags. They use old clothes to make cloth bags (布袋), and send them to their parents aspresents. They also ask their parents and friends to use cloth bags instead of plastic ones. They think it istheir duty to protect (保护) the environment. 1. People in China have to _____ now. [     ]A. throw plastic bags here and there B. collect plastic bags in the street C. pay for using plastic bags at shops and supermarkets D. use free plastic bags at shops and supermarkets 2. China made this rule because plastic bags were bad for the _____. [     ]A. environment B. litter C. shops D. supermarkets 3. The Chinese people are encouraged to bring _____ for shopping. [     ]A. no bags B. free plastic bags C. their own bags D. super-thin plastic bags 4. Some students in Chongqing _____. [     ]A. ask their parents to make cloth bagsB. make cloth bags themselves C. pick up plastic bags everywhere D. 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. Some students in Chongqing begin to make their own shopping bags.D. To protect the environment, free plastic bags have been banned in China.