题目内容：

阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。

We all know clean water is important for good health. But now we also know we should watch 1. we keep our water in. Plastic bottles hardened with a dangerous material 2.(call) BPA can release a chemical into our water that harms our bodies. Since 2011, many countries 3.(ban) plastic with BPA from use in food containers and baby bottles. But are other non-BPA plastics safe?

Plastic labeled BPA-free might use other chemicals that have 4.(harm) health effects. 5.(Study) have shown that low levels of those chemicals might have the same effects as BPA. So, what should people do? The 6.(good) material to drink from is glass, 7. has no chemicals that can poison water.

Another good choice 8. a drink container is stainless steel. Stainless steel bottles are better than aluminum bottles, which are covered with a thin plastic 9.(protect) the metal from acids. There are many good food-grade stainless steel water bottles on the market.

If you do decide to use a reusable plastic water bottle, avoid 10.(keep) it in the sun. Sunlight and hot liquid speed up the release of chemicals into your drinking water.