以下是一封符合要求的英语信件，包含了五条句子：

Dear [收件人姓名],

I especially enjoyed watching the lions and tigers. They were so powerful and beautiful. I also saw some cute monkeys and elephants. It was a fun day and I learned a lot about different animals.

I hope you have a chance to visit the zoo soon. Take care and keep in touch.

[你的名字]