假定你是李华，你的好友张明邀请你参加他的 18 岁生日聚会，你因故不能参加。请用英语给他 写一封电子邮件。内容包括：
1．词数 100 左右；
Dear Zhang ming
How are you? ____________________________________________________________________
Dear Zhang Ming,
How are you? Thanks so much for inviting me to your eighteenth birthday party. Happy birthday to you! I’d like to go, but I am afraid I can’t be present. I’m so sorry.
My mother had a fall yesterday evening and got hurt badly in her right leg. I have to look after her because my father is away on business. It is really a pity to miss your birthday party.
Here, I’d like to express my best wishes in advance. I have just bought a wallet for you, which I hope you would like. The present will be delivered to you by express and will get to you tomorrow.
Sorry again for my absence.