Ihadbeensittinginmyseatforatleasttwohours,waiting.AthetraintostartBforthetrainstartingCforthetraintostartDforthetrainstart

Question

I had been sitting in my seat for at least two hours,waiting_____.A the train to start
B for the train starting C for the train to start D for the train start

Answer 1

c
wait for sb/sth to do sh