a,
2. the money stolen was never found
3.bỏ it
5.bỏ the
b,
1,I apologised to him for not being able to arrive on time.
2.Look! The sun is setting behind the mountains
3,In my life, I have never been to Pac Bo Cave.
4,It's difficult to get in touch with the manager of the company.
5.My uncle has given up smoking for one year