I CAN'T FIND MY BOOK ANYWHERE. I_______ HAVE LEFT IT ON THE TRA...

29. - File thứ 4: anh12cb_231201916
File thứ 4: anh12cb_231201916

29. I can't find my book anywhere. I_______ have left it on the train. I am not sure.

A. might

B. must

C. needn't

D. should