*一、单项选择
（ ） 1. When _______ your mother born?
A. does B. did C. was D. were
（ ） 2. —How long did you study here?
—I studied here _______ two years.
A. in B. at C. of D. for
（ ） 3. The box is _______ heavy for him _______. Let’s help him.
A. very; to carry B. too; to carry C. too; carry D. very; carrying
