1. (2022九下·铜仁竞赛) 完形填空

American people have the habit of saying thank you whenever something kind is done for them or something polite is said to them, no matter how easy or casual the thing is. This habit is1by people of many2countries. You should say "Thank you" when someone3 you the salt on the table, or when someone 4aside to let you 5 in a narrow corridor, or when someone 6ahead of you keeps the door open 7you, when someone says your work is well 8 or says you have bought a nice thing, or says your city is very beautiful. "Thank you" is 9 not only between strangers or new acquaintance, 10between friends and colleagues, parents and children, brothers and sisters, husbands and wives. Parents often tell 11  children that they should say "Thank you" in answer to a 12word or act when they are only four 13five years old. Perhaps that's 14 almost everyone has 15 this habit.