请选择DCBA5x/B.T John, work hard _______ you will make much progress.,N1`,T7I4l+P4?:e5m6Q
A. or,N1`,T7I4l+P4?:e5m6Q
B. nor,N1`,T7I4l+P4?:e5m6Q
C. but,N1`,T7I4l+P4?:e5m6Q
D. and,N1`,T7I4l+P4?:e5m6Q