Human beings need to drink for their survival.Water ranks __high__on the list of all-time safe fluids.But not all water is as safe as once __thought__.Recent tests of water fountains in several U.S.cities show that many fountains give water containing large __amounts__of lead(Pb),a poisonous metal.A recent study of 900 water fountains in Los Angeles _revealed___that half of the fountains __tested__contained higher amounts of lead than the _amount___the experts
consider __safe__.In other cities __similar__results of tests were announced:too much lead in many,though ___not all_,drinking fountains. Water doesn‘t normally contain any lead,but when it passes through pipes,it can __be contaminated__. People who drink the water __take in__the lead. An adult‘s body passes most of the lead__out of__the body,but children‘s __body__retains more than half the lead __swallowed__.This makes children more likely to be affected.Lead
can damage the kidneys ,cause __hearing loss__and impair learning and memory .as many as____four million children in U.S.A.already have high levels of lead in their bodies. Most of this lead comes from __breathing air__polluted with the metal.They can _pick___it up from eating dirt or paint chips containing lead.In __an attempt__to limit the lead in water fountains,officials recently suggested that fountains __found__to have too much lead be replaced or repaired.And that certainly requires a lot of money
还好!采纳!
追答谢谢采纳!