Do you still get free plastic bags from the supermarkets? Things have changed.
       China has banned（禁止）free plastic bags in  shops and supermarkets，and people have to pay for using plastic bags. The rule started on June 1st. It came because our country tried to make less litter. Making super-thin 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 bags for shop ping.
       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，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.
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人体主要的内分泌腺有____、____、____、____、____和____等。

化学就在我们身边，它与我们的生活息息相关．请按要求填空

①自来水生产过程中能凝聚水中悬浮物的是 ____（填物质名称）；

②用活性炭去除冰箱中的异味是利用了活性炭具有 ____性；

③常作气体燃料的一种有机物是　 ____（填化学式）；

④可以做食品干燥剂的金属氧化物是 ____　（填化学式）；

⑤能使带火星的木条复燃的气体是 ____；该气体在空气中的体积分数约为 ____