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It′s light，clean and convenient，after using it you throw it away．Do you know what it is? It′s the disposable(可任意使用的)food box．We can see it every day and everywhere：in restaurants，schools and streets．

    Every year，Chinese people use about 6．5 billion food boxes．But they have found that half of the disposable food boxes are made of cancer—causing materials．Some of these materials may get even worse with hot food and oil.”Day after day，the results can harm our body parts，″said the expert Dong Jinshi．Polypropylene(聚丙烯)is a safe material for disposable food boxes．But one ton of Polypropylene costs 11,000 yuan while the same amount of unsafe plastic costs less than 2，000 yuan．To save money，some food box makers choose unsafe materials．

    Experts also warn parents and students not to put food into black plastic bags．Some of these plastic bags are made of unsafe plastic．They could do harm to people, health，too．

    To eat safely，scientists ask US to use brown paper bags instead of plastic bags．

  1.People often use the disposable food boxes because they are very     .

     A．convenient    B．1ight    C．clean       D．a(chǎn)ll of above

 2．The underlined sentence in this passage means that       ．

    A．If people put hot food and oil in。the material will be OK．

    B．If people put hot food and oil in．the material will pollute food more and be more harmful to people′s health．

    C．If people put hot food and oil in．the food will be more delicious．

    D．If people put hot food and oil in．the boxes will be broken．

 3．Why do people choose unsafe plastic to make the disposable food boxes?

    A．They can save money．

    B．They can make food delicious．

    C．They are convenient．

    D．They are good for people′s health．

 4．If a food box maker wants to make 6000 food boxes made of Polypropylene and at on of each kind of plastic can be made into 3，000 food boxes，how much more will be spent at least?

    A．￥2，000     B．￥4，000    C．￥9，000       D．￥18，000

 5．Which of the following is not true?

    A．Food boxes made of Polypropylene are safe．

    B．Black plastic food boxes are OK．

    C．Experts advise people to use brown paper bags．

    D．We must find ways to get safe food bags or boxes cheaper．