单项选择题
He is so shy that he() speaks in the public.
A. often B. frequently C. seldom D. sometimes
单项选择题 In countries where a solar calendar was adopted, the length of each year need to be () in order to have the same number of months in each year.
单项选择题 Had he worked harder, he () the exams.
单项选择题 ()I cannot keep up with my classmates
