62. Several factors determine the amount of pollen in the air. Which of the following is NOT one of them?
(A) weather
(B) mood
(C) place
(D) season

Hay fever(過敏性鼻炎) is a seasonal allergy(過敏) to pollens(花粉). The term “hay fever,” however, is a less than adequate(足夠) description since such an attack can be brought on by sources other than hay-producing grasses and since an attack of this allergy does not include a fever. The cause of hay fever can be quite varied. Hay fever is generally caused by airborne pollens, particularly ragweed(豚草) pollen. The amount of pollen in the air is largely dependent on geographical location, weather, and season. In the eastern section of the United States, for example, there are generally three periods when pollen from various sources can cause intense(強烈的) hay fever suffering: in the springtime months of March and April when pollen from trees is prevalent(普遍的); in the summer months of June and July, when grass pollen fills the air; and at the end of August, when ragweed pollen is at its most concentrated levels. What results from an attack of hay fever is not a fever. Instead, a person with hay fever will suffer symptoms such as red and itching eyes, a swollen and runny nose, and repeated bouts of sneezing.