单选题 If you are like most people, your intelligence varies from season to season. You are probably a lot sharper in the spring than you are at any other time of the year. A noted scientist, Ellsworth Huntington (1876-1947), concluded from other men’s work and his own among peoples in different climates that climate and temperature have a definite effect on our mental abilities.
He found that cool weather is much more favorable for creative thinking than is summer heat. This does not mean that all people are less intelligent in the summer than they are during the rest of the year. It does mean, however, that the mental abilities of large numbers of people tend to be lowest in the summer.
Spring appears to be the best period of the year for thinking. One reason may be that in the spring man’s mental abilities are affected by the same factors that bring about great changes in all nature.
Fall is the next-best season, then winter. As for summer, it seems to be a good time to take a long vacation from thinking!

单选题 Ellsworth Huntington decided that climate and temperature have______.
A. a great effect on everyone’s intelligence
B. same effect on most persons' intelligence
C. some effect on a few persons' intelligence
D. no effect on most persons' intelligence

单选题 It seems that the cold winter______.
A. increases the ability to think
B. is the best time for thinking
C. is better for thinking than is very warm weather
D. decreases the ability to think

单选题 One possible reason why spring is the best season for thinking is that______.
A. all nature, including man, is growing then
B. it lasts longer than the other seasons
C. it is not too warm and not too cold
D. both B and C

单选题 According to the passage, any vacations from thinking should be taken______.
A. several times throughout the year B. during spring and fall
C. during the summer D. as seldom as possible