用适当的介词(under，for，in，with，at，on)填空。(18分)
（1）What can I do ______ you?
（2）Can you go shopping ______ me?
（3）Ann is good  ______ painting.
（4）I usually visit my grandpa ______ Sundays.
（5）There's a ball ______ the chair.
（6）My father watches TV ______ the evening.