Directions: Read the following passage.

     Lead poisoning (铅中毒) occurs when lead is present in high levels in the blood of a person. It is one of
the most common medical problems found in children. And it's important to recognize the presence of lead
in children's bodies because lead is very harmful.
     Children have the tendency to go around and put things in their mouths like paint peelings. This is one
of the main causes of lead poisoning. It has also been found that children born in poor families have higher
chances of getting exposed to lead.
     Some of the common symptoms of lead poisoning in children are headaches, stomach pains hair loss,
muscle weakness, and weight loss, etc.
     Lead poisoning can have severe effects and can lead to heart diseases, kidney diseases and neurological
(神经系统的) problems. It can also result in mental dullness and a low I.Q. level. There have been cases
where lead poisoning proved to be terminal for children.
     It's difficult to easily recognize whether a child is affected by lead poisonig, as the symptoms of this
disease can occur due to some other medical problems. Therefore, children under the age of 6 should
regularly be checked to know the level of lead in their blood through blood tests. It's possible to completely
cure a child with lead poisoning through treatment. Usually the oral medicine chelator (螯合剂) is given to
the children. Sometimes, children are given an injection (注射) for reducing the lead level. Children who
have very high level of lead in their blood would need treatment for a long period of time and would also be
put on a special diet.
     Parents have to take certain precautions to lower the chance of lead poisoning in children. Cleaning the
house regularly and removing shoes at the door after coming in from outside will prevent the lead particles
from entering the house. Children should be put on a healthy diet, containing high proportionsnclud of
calcium and iron, such as eggs, milk, fruits, potatoes, etc., which helps to keep the lead levels in control,
in the children's bodies.
     In short, it's a must to be cautious and careful, and protect your children from the horrible consequences
of lead poisoning.