You should ________ studying English if you want to learn a new word by heart．You can _______ the word a few times．
A.keep; keep onB.keep on; keep on repeatingC.keep on; keep repeatingD.keep; keep repeat在线课程C
keep on doing sth．相当于go on doing，指动作、行为有间歇之后继续进行，也指长期坚持某事；keep doing sth．强调反复性。