基础训练篇（2）
You may wonder why we have a holiday in summer (1) _________ winter, but not in spring (2)_________ autumn. There are some reasons (3)_______________ it. Like most people, your intelligence（智力）changes from season to season. You are properly a lot sharper in the spring (4)_______________ you are (5)___________ any other time of the year. Ellsworth Huntington, who’s well known to us all concluded from other men’s work and his own among people in different climates that climate and temperature have a clear effect  (6)___________ our intelligence. He found that cool weather is far better for creative thinking than warm weather. This  (7)____________ mean that all people are not  (8)_______________ quick at learning in the summer as they  (9)_________________ during the rest of the year. It tells us, (10)________________, that intelligence of large numbers of people seems to be lowest in the summer.