Mr. Brown is walking in the park. He is very tired. He wants to have a rest. He sees a red chair under a tree over there. So he walks to the chair. There is another man in front of him. He is walking to the chair， too. He has a board(木板) in his hand. Mr. Brown is very worried. He begins to run quickly. The man sees him. He begins to run， too. But Mr. Brown is faster. He gets to the chair before the man. He is very happy. When the man comes， Mr. Brown is sitting on the chair. He says nothing but gives Mr. Brown the board. The board says， “Wet Paint(油漆未干)!”

想一想:

Why does Mr. Brown run to the chair? And why does the man with a board run to the chair， too?

難度系數(shù):★★