短文改错I will never forget my experience during the shanghai Ex

短文改错I will never forget my experience during the shanghai Expo,that has disturbed me a lot.
I will never forget my experience during the shanghai Expo,that has disturbed me a lot.it was a saturday noon but many visitors were having a lunch on the grassland.I saw a foreign couple and a Chinese couple who have just finished their lunch.Without some hesitation ,the chinese couple threw their leftover food on the grass.Astonishing,the foreign couple said,"it's no good damaging the environment by littering carelessly."The word of the foreign couple struck my mind.It is time that we strengthen our awareness of environmental protection.The phenomenon for spitting and littering in public places should banned completely.