21. He has ____ eight-year-old son who has ___ gift for playing the piano.
A. a, a B. an, the C. an, a D. the, a
22. ____ with enough equipment for the experiment, they are expecting to finish it as soon as possible.
A. Supplied B. To be supplied C. Supplying D. To supplied
23. Early ___ the morning of May 1, we started off ___ the mountain village.
Ain, for B. in, to C. on, / D. on, for
