One day a teacher walked into the classroom with a glass of water in her hand. Her students (ask) to tell her the weight of the glass of water she was holding. They shouted out dinerent answers. of water doesn't matter. It all (depend) on how long I hold it. If I hold it for a few minutes, it's quite light. If I hold it for an hour, weight might make my arm ache (疼痛). If I hold it for a day, my ann will feel very painful, forcing me (drop) the glass to the floor. The weight of the glass of water doesn't change, but the longer I hold it, the (heavy) it becomes.''
Seeing the surprised look on her students' fhccs, she continued, a smile on her face, the teacher replied. "Actually, the exact weight of this glass. The thingsmake you feel stressed are just like this glass of water. Think about them for while and nothing happens. Think about them a little longer and you begin to ache. Think about them all day long, and you will feel (terrible) painful — unable to do anything else until you drop your problems and (worry). If you still feel the weight of yesterday's stress, it's time to put the 'glass' down.