变应原

例句：

1. 1. The doctor prescribed a new allergen for her to avoid.
   医生为她开了一种新的过敏原以避免。
2. 2. Allergens can cause severe reactions in sensitive individuals.
   过敏原在敏感个体中会引起严重的反应。
3. 3. The study found that exposure to certain allergen could lead to asthma.
   研究发现，暴露于某些过敏原可能会导致哮喘。