二、单项填空（共16小题；每小题0.5分，满分8分）
15.This experience shows that ____ good knowledge of first aid can make ____ real difference.
A. a, a B. a, / C. the, a D. the, the
16. The class __________ 80 students is hard to manage.
A .consisting of B. consists of C. making up of D. made up
17.He asked us to ________ him ______ carrying through their plan.
A. assist; with B. help; to C. assist; in D. help; with
