J.
reason K. performance L. wet M. next N. environmentally O. rest If you are like most people, your intelligence varies from season to season. You are probably a lot sharper in spring than you are at any _____1____ time of the year. Spring appears to be the _____2 ____ period of the year for thinking. One _____3 ____ may be that in spring man's _____4 ____ powers are affected by the same factors that bring about great changes in all nature. Autumn is the _____5 ____ best season, then winter. _____6 ____ for summer, it seems to be a good time to _____ 7____ a long vacation from thinking! It has been found that _____8 ____ weather is much more favorable for creative _____ 9____ than is summer heat. This does not mean that all people are less intelligent in summer than they are during the _____10 ____ of the year. It does mean, however, that the mental powers of large numbers of people tend to be lowest in summer.