One evening I went out and left my 17-year-old son in charge of his 8-year-old brother and 4-year-old sister．On this occasion, the work was made less troublesome by the presence of his girlfriend．I left with complete confidence that the older children would do a wonderful job of babysitting the younger children．Later, I discovered that complete confidence was the last thing I should have left home with．
I had decided to return home earlier than planned so that my son and his girlfriend could go out．I called home with this happy news．But instead of hearing his cheerful, grateful voice on the other end of the line, all I heard was the sound of a telephone ringing．
It was, I should point out, after 10 p．m．,when the two younger children should have been in bed, and when the two older children should have been answering the phone．“I’ll give him a lesson,” I said． I decided they must be outside．Why they might be outside at 10:30 on a winter night I had no idea, but it was the only explanation I could come up with．
Finally, in desperation, I called his girlfriend’s house． After what seemed like countless rings, his girlfriend answered．“Yes,” she said brightly, “He’s right here．”
He came on the phone．I was not my usual calm, rational（理智的）self． After all, one of the rules of survival for modern parents is that you can’t trust modern teenagers．“Where are the children?” I said．He said they were with him．They had done nothing wrong．My son had taken the younger children over to his girlfriend’s house just for ice cream and cake．This was too good to be believed． Well, it turns out that I shouldn’t have believed it．It was only part of the truth．
The following Saturday evening we were at my parents’ home, celebrating my birthday．My oldest son gave me the children’s gifts．Mounted and framed were a series of lovely color photographs of my children, dressed in their best clothes, and wearing their most wonderful expressions．They are pictures to treasure a lifetime, all taken by the father of my son’s girlfriend．
The author went out and left her eldest son in charge of the younger children because         ．   

A．she knew that her eldest son was a good baby-sitter

B．she thought it no hard work to take care of the younger ones

C．she believed he could do well with his girlfriend’s help

D．she could not find a baby-sitter on that winter night

When the author called home that evening, she found that           ．

A．two younger children had already been in bed

B．the children were preparing a birthday gift for her

C．her son was quarrelling with his girlfriend

D．there was no one answering the telephone

What might the children do that evening?

A．They had a birthday party．	B．They framed some photographs．
C．They had their pictures taken．	D．They made some beautiful clothes．

What does the author intend to tell us by the story?

A．Modern teenagers are not worth trusting．

B．It is no easy job to look after young children．

C．It’s no good to have a girlfriend at an early age．

D．Her children have a caring and tender heart．