第一册课本听力(上)Unit7 intergrating skills

　　Dear Editor,I live in Paris,France.In my country there is a famous site,called the Chauvet Caves.I am very worried about it because some of the cave paintings have been destroyed by air pollution.No,the pollution does not come from cars or factories,but from human begings.
Thousands of tourists visit the caves every year.The carbon¹ dioxide² from their breath³ is damaging the paintings.I think one way to solve the problem is to put glass walls in front of the paintings.Second,the number ofvisitors should be limited.And we should build a website where people can look at the pictures and paintings.
Yours sincerely,Sophie

1 carbon   

n.碳元素

参考例句：

• Diamonds are pure carbon.钻石是纯净的碳。
• Carbon is an element,while carbon dioxide is a compound.碳是一种(化学)元素，而二氧化碳则是一种化合物。

2 dioxide   

n.二氧化物

参考例句：

• The oxygen and the carbon combine to form carbon dioxide.氧和碳化合，形成二氧化碳。
• Carbon dioxide is the largest contributor to the greenhouse effect.二氧化碳太多是道致温室效应的最主要原因。

3 breath   

n.呼吸，气息，微风，迹象，精神，一种说话的声音

参考例句：

• I'm just going out for a breath of fresh air.我正要出去呼吸新鲜空气。
• While climbing up the stairs the old man always loses his breath.那老人上楼时总是气喘吁吁的。