帮忙看一下下面3句话有没有错误,

问题描述:

帮忙看一下下面3句话有没有错误,
1)I am Zhang Hua ,a junior of Beijing University.
2)I am Zhang Hua ,a regular customer of your shop.
3)I am Zhang Hua ,a tenant of Room 111 in building 5.

1 2 没有意见 3 貌似用the代替a好些