It was nine on a cold winter night.I hurried to go home from work（1）

on

on

my motorbike.
    At the last crossing，while I（2）

was waiting

was waiting

（wait） for the green light，I saw an old man walking toward me.He（3）

stopped

stopped

（stop） me，and I felt a little nervous.The old man said slowly， "Excuse me.Could you please help me？" I looked at him up and down.He looked about 70 years old.
    The old man took out a 10-yuan bill（4）

and

and

said to me. "You see the old lady over there？She is selling baked （烤） sweet potatoes.Could you just take the money and buy one from her？" He pointed at an old lady selling something about fifty（5）

meters

meters

（meter） away in the corner.
    "But why don't you go and buy it（6）

yourself

yourself

（you）？" I was puzzled （迷惑的） .The old man continued， "That old lady is my wife and it's her（7）

first

first

（one） day to sell baked sweet potatoes.Just now I called her.She told me that there was only one sweet potato left and she wouldn't go home until all the sweet potatoes were sold out.But I know she can't stand the cold because her legs hurt.I'm very worried about her."
    At that time，I could（8）

understand

understand

（understand） why the old man asked me（9）

to buy

to buy

（buy） his wife's sweet potato.I felt really warm and moved.Without taking the money，I rode to the old lady quickly and bought the last one.As I waved goodbye to the old man，I could see him standing there with a（10）

thankful

thankful

（thank） smile.