Happy Christmas!
祝你圣诞快乐!
A merry Christmas and a happy New Year!
祝你圣诞愉快,新年快乐!
Please send my Christmas greetings to Susan.
请代我向苏珊表达我的圣诞祝愿!
Thanks. The same to you.
谢谢你,也祝你圣诞快乐!