填空题
What is .required in many different situations in American culture?
An expression of ______ .
填空题
For what do people say "thank you"?
They say "thank you" for big favors as well as for ______ .
填空题
What is not necessary for other's help?
Excessive ______ .
填空题
What will you say when your adviser helps you to edit your paper?
"Thank you for your help. " or "I really ______ . /
填空题
How might your adviser feel if you keep on mentioning this kindness?
The advisor might feel ______ .