阅读下面短文，掌握其大意，然后从各题所给的四个选项(A、B、C和D)中，选出最佳选项。
The old man went slowly into the restaurant．A young waitress named Mary 1 him go toward a table by the window．
Mary ran 2 to him, and said, “Here, Sir．Let me give you a 3 with that chair．”
She pulled the chair away from the table．Steadying(使平稳)him with one arm, she helped him move 4 the chair, and get 5 seated．Then she leaned his 6 against the table where he could reach it．In a 7 , clear voice he said, “Thank you, Miss．And bless you for your kind 8 ．” “You're welcome, Sir．” She replied．“And my name is Mary．I'll be back in a moment, and if you need 9 , just wave at me!”
10 he had finished a hearty(丰盛的)meal of pancakes, bacon, and hot lemon tea, Mary 11 him the change．She helped him up from his chair, and out from behind the table．She handed 12 his walking stick, and 13 with him to the front door．
Holding the door 14 for him, she said, “Come back and see us, Sir!” He turned with his whole body, smiled, and nodded．“You are very kind．” he said softly． 15 Mary went to clean his table, she was very 16 ．Under his plate she found a business card and a note．Under the note was a one-hundred-dollar bill．
The note 17 ：“Dear Mary, I respect you very much, and you 18 yourself too．It shows by the 19 you treat others．You have found the secret of happiness．Your kind gestures will shine through 20 meets you．”
The man she had waited on was the owner of the restaurant where she worked．This was the first time that she, or any of his employees had ever seen him in person．
