请选择DCBA3B-r/f;K,m My brother while he his bike and hurt himself .+O,t6o;B0E,z,D
A. fell , was riding+O,t6o;B0E,z,D
B. fell , were riding+O,t6o;B0E,z,D
C. had fallen , rode+O,t6o;B0E,z,D
D. had fallen , was riding+O,t6o;B0E,z,D