根据课文所学将划线部分改正。
1. She plays piano at home. __________
2. What does you do on Saturdays? __________
3. Lily should learn on Henry. __________
4. She often helps her mum doing the housework. __________
5. Are it difficult to play the piano? __________
6. She have dinner at 7:00 pm. __________
7. Betty practise it at home. __________