完成下列各选项 Expressing gratitude is an important form. of good manners． Nowadays more and more people in China have found it s high time to 11 a thankful heart for the young． Everyone likes to get praised and appreciated． Gratitude is the greatest of virtues, which lets others smile and makes the world more beautiful． You just need several minutes to write down a thank-you note, but it brings much joy to the 12 We live in a society where we enjoy the different services of others． But 13 of them should be taken for granted． Gratitude is also a kind of 14 in life． In developing gratitude for every moment-- for the simple joys and even for the 15 times--we come to truly enjoy and appreciate life． Then we are able to see the 16 that surrounds us． Try to write a thank-you letter to your parents for working hard to 17 you a happy life． Be grateful to your teachers because of their 18 with your studies and character building ．Say thanks to your friends who 19 both your happiness and sorrow． We are sure it will bring them much joy and add 20 into your own life as well．