It is said that each year China consumes 15 billion lunch boxes, _______ which over a half are not q ualified products. These cheap lunch boxes pose threat to h_______. They contain _______ (有毒的) chemicals, which could harm human digestive and nervous systems, and even _______ cancers. Experts suggest that consumers take their own table-ware _______ them rather than use that _______ (提供) by restaurants. If you really need to use a restaurant lunch box, _______ carefully first. Those which break or leak easily, or smell t_______ are not suitable for you to use them _______ your lunch container. If you are careful about what you eat your lunch from , you will also do your part in p______ our environment at the same time.