根据课文内容，填写合适的单词完成句子，每空一词。
1. Chinese traditional art is amazing. It has many special . And they can turn common things into objects of .
2. Sky lanterns are used at festivals and other . People see them as of happiness and good wishes.
3. Paper cutting has a history of over 15 . People fold paper and then cut them into beautiful shapes with . They symbolize (象征) for good luck and happiness.
4. Chinese clay art is also famous. The clay pieces look small but . The process is complex (复杂的). People shape the pieces, dry them and fire them at a high . Finally, they polish them and paint them. It takes several weeks to everything.