My grandfather _____ smoking, but only smokes when he is free. [ ]

She promised to ______ at the meeting but she didn’t ______.

May I speak to Robert— .

More than 36 million Chinese children are receiving piano training, but quite a few have little ______ in the piano and some even hate it.

Although he was really disappointed, he _______ a weak smile.— He is always caring about others` feelings.