Asthma, a bronchial condition, is much less common ailment than hay fever, an allergic inflammation of the nasal passages.
哮喘是一种支气管疾病，比花粉热（一种鼻道的过敏性炎症）要少见得多。
3
If identical twins are more similar to each other with respect to an ailment than fraternal twins are, then vulnerability to the disease must be rooted at least in part in heredity.