why do people put on weight?

why do people put on weight? put weight on put on weight put my weight on Why do people feel stronger on Sundays? Why do people feel stronger on Snudays? why do people feel stronger on weekends? put on weight 中的 on 是什么词性 he has put on weight during th put on a lot of weight Do people put too much emphasis on learning practical skills put weight on与put on weight意思一样吗 为什么