阅读文章，回答下列问题。
Gift giving is different from culture to culture and person to person.
When giving gifts, sometimes color is important. For example, for many Chinese people around the world, red is a lucky color, and people often like to wrap gifts in this color. However, did you know that in Korea, red is a color of death? That is why you should not wrap（包装） your gifts in this color if you are giving a gift to a Korean person. What about westernn countries? In western countries, the color of wrapping paper is not really important. But color does matter when giving flowers, especially roses. You should not give red roses to a western person you don't know very well because they are a symbol of love. You could give yellow roses instead as these are a symbol of friendship. You could also send pink roses as gifts to say thank you.
What other things should you remember when giving gifts to someone from a different culture? Well, one thing you should keep in mind is the person's religion(宗教). When choosing a gift for a Muslim (穆斯林) or Jewish friend, you should never get food including pork, or things made from pigskin. Another thing that you should not get for a Muslim person is alcohol (酒).
In which country do people think red is the color of death?
How can we show our friendship to the western friends?
What gift doesn’t a Muslin friend like?
How many colors are mentioned(提及) in this passage? What are they?
What's the main idea of this passage?