Don't ask what this country can do for you． Ask __________ what you can do for this country．（ ）
A．yourselvesB．youC．themselvesD．them
I feel upset because I am too heavy．
____________ do more exercise to lose some weight？（ ）
A．Why don'tB．Why notC．Why not to
Mrs．White，can I leave my homework for tomorrow？
I'm afraid not．Don't ___________what you can do today till tomorrow．（ ）
A．put offB．get offC．take off
Mum，I'm going climbing．Must I clean the room now？
No，you_____________．You can do it this evening．（ ）
A．can'tB．mustn'tC．needn't
Look! A woman with three children____________ crossing the street．
Let's help them．（ ）
A．isB．areC．was
Why are you so excited？
Nancy invited me ___________ on a trip to Dongjiang Lake just now．（ ）
A．to goB．goC．going