Two good friends, Sam and Jason, met with a car accident on their way home one night. The next morning, Sam woke up blind. His legs were broken. The doctor, Mr. Lee, was standing by his bed，looking at him with a thoughtful expression. When he saw Sam awake, he asked，"How are you feeling, Sam？"Sam smiled and said，"Not bad, doctor. Thank you for doing the operation(手术)." Mr. Lee was moved by Sam. When he was leaving, Sam said, "Please don't tell Jason about it." "...OK," Mr. Lee replied.
Months later when Jason's wounds (伤)healed(愈合), Sam was still very sick. Neither could he see nor walk. What he could do was just stay in his wheelchair all day long. At first, Jason stayed with him for a few days. But days later, Jason felt very discouraged and embarrassed to spend time staying with a disabled man like Sam. So he went to see Sam less and less. He made new friends. From then on, he didn't go to visit Sam any more. Sam didn't have any family or friends. He felt very sad.
Things went from bad to worse. Sam died a year later. When Jason came, Mr. Lee gave a letter to him. It was from Sam. In the letter Sam said，"Dear Jason, I am disabled. But I want you to be a healthy man. So I gave my eyes to you so that you can enjoy life as a healthy man. Now you have new friends. I'm glad to see that you are as healthy as usual. I'm glad you live a happy life. You are always my best friend...Sam". When he finished reading the letter, Mr. Lee said, "I've promised that I will keep this secret until Sam is gone. Now you know it." Jason stood there. Tears ran down his face.
4. The reason why Sam thanked Mr. Lee was that ．
A. Mr. Lee was very kind and friendly to him
B. Mr. Lee came to see him early in the morning
C. Mr. Lee did the operation according to his wish
D. Mr. Lee saved both his and Jason's lives
5. Which of the following happened according to the order of time?
a. Jason made new friends.
b. Sam gave his eyes to Jason.
c. Sam and Jason were caught in a car accident.
d. Sam was disabled and needed friends.
e. Sam died and Jason knew the truth.
A. d，a，c，b，e B. d，c，b，e，a
C. c，b，d，a，e D. c，d，b，e，a
6. We can infer (推断)from the passage that ．