来源：BBC英语教学
原标题：Pet dogs ‘may help children avoid asthma’ 宠物狗“可能有助儿童避免患哮喘”
dog瑞典的一项大型研究项目发现，家中有宠物狗的低龄孩子日后不大可能患哮喘。 BBC 记者 Michelle Roberts 有以下报道：
Many people are allergic to dogs， or at least the dead skin cells and saliva that they shed as they groom themselves.
But a new piece of research from Sweden suggests early exposure to these pets could cut a child‘s future risk of allergy. Living with a dog in the home in the first year of life was linked to a 13% lower risk of asthma in later childhood among the 650，000 children the authors tracked.
The researchers say this fits with the hygiene hypothesis which favours exposure to dust and dirt to improve our tolerance of common allergens. But for a child who is already allergic to dogs， buying a puppy would not be a good idea.
词汇表
allergic （生理上）过敏的，有过敏反应的
saliva 唾液
shed 掉下，流出
tracked 跟踪调查的
hygiene 卫生；保健
tolerance 容忍度，耐受性
allergens 过敏源
测验
请听报道并回答下列问题。
1 What do dogs lose when they groom themselves？
2 When is it most beneficial for children to have a dog at home， according to the study？
3 True or false？ Researchers believe that children exposed to dirt are less affected by common allergens later in life.
4 Do the researchers recommend that every family has a pet dog at home？
答案
1 What do dogs lose when they groom themselves？
Dead skin cells and saliva.
2 When is it most beneficial for children to have a dog at home， according to the study？
According to the study， living with a dog in the home in the first year of life was linked to a 13% lower risk of asthma.
3 True or false？ Researchers believe that children exposed to dirt are less affected by common allergens later in life.
True. This is called the hygiene hypothesis.
4 Do the researchers recommend that every family has a pet dog at home？
No. They say that this wouldn‘t benefit children who are already allergic to dogs.
BBC英语教学
