Simply draw lace decoration on colored paper, write numbers in the upper part of colored paper and write riddles in the middle.
The answer is also copied on the answer sheet according to the number, which is convenient for receiving the prize.
The content of the riddle
Mystery: Unknown (name a topic). Answer: geometry
Mystery: It won't rain for three days (enter city name). Answer: Guiyang
Mystery: Go meets an opponent (to use an idiom). Answer: There is no distinction between black and white.
Mystery: Nothing is (making a solar term). Answer: White deer.