The volunteers are doing _____ difficult and important work; they share ____ common goal to help people in need.
A. a; a B. a; the C. 不填; the D. 不填; a
The volunteers are doing _____ difficult and important work; they share ____ common goal to help people in need.
A. a; a B. a; the C. 不填; the D. 不填; a
D