My teenage son Karl became withdrawn after his father died. As a single
parent, I tried to do my best to talk to him. But the more I tried, the more he
pulled away. When his report card arrived during his junior year, it said that he
had been absent 95 times from classes and had six falling grades for the year. In
this way he would never graduate. I sent him to the school adviser, and I even
begged him. Nothing worked.
　　One night I felt so powerless that I got down on my knees and asked God for
help. "Please God, I can't do anything more for my son. I'm at the end of my
rope. I'm giving the whole thing up to you."
　　I was at work when I got a phone call. A man introduced himself as the
headmaster. "I want to talk to you about Karl's absences." Before he could say
another word, I choked up（哽咽）and all my disappointment and sadness over
Karl came pouring out into the ears of this stranger. "I love my son, but I just
don't know what to do. I've tried everything to get Karl to go back to school and
nothing has worked. It's out of my hands. " For a moment there was silence on
the other and of the line. The headmaster seriously said, "Thank you for your
time",and hung up.
　　Karl's next report card showed a marked improvement in his grades.
Finally, he was even on the list of the best students at school. In his fourth year, I
attended a parent-teacher meeting with Karl. I noticed that his teachers were
surprised at the way he had turned himself around. On our way home, he said,
"Mum, remember that call from the headmaster last year?" I nodded. "That was
me. I thought I’d play a joke but when I heard what you said, it really hit me how
much I was hurting you. That’s when I knew I had to make you proud."

1. Which of the following has the similar meaning as the underlined word "withdrawn" in the  first paragraph?

A. preferred to stay alone at home    
B. refused to go to school
C. refused to talk to others          
D. began to dislike his mother

2. There was silence on the other end of the line because _____.

A. the caller was too moved to say anything to the mother
B. the caller waited for the mother to finish speaking
C. the caller didn't want the mother to continue her talk
D. the caller was unable to help the mother

3. Who was it that telephoned Karl's mother that day?

A. The headmaster.          
B. The school adviser.
C. Karl himself.              
D. The passage doesn’t tell us.

4. From the passage we can learn that _____________.

A. children in single parent families always have mental problems
B. mother's love plays an important role in teenagers' life
C. parents should give their children as much help as possible
D. school education still works well without support from parents