关于帧中继，下面说法不正确的是

A．在帧中继中，定义两种不同数据速率，即承诺速率(CI和接入速率

B．帧中继不依赖于ISDN，现在有许多与ISDN独立运营的帖中继网络

C．帧中继依赖于ISDN

D．帧中继使用的地址和ISDN使用的地址概念相同，都采用DLCI标识连接

Ann Curry is a famous news presenter of the NBC News "Today" show. When she was 15 she happened to walk into a bookstore in her hometown and began looking at the books on the shelves. The man behind the counter, Mac McCarley, asked if she’d like a job. She needed to start saving for college, so she said yes.

What particularly gives her the feeling of pride
[A] Helping people through work. [B] Reporting interesting stories.
[C] Being able to do different jobs well. [D] Paying through her college education.

Ann worked after school and during summer vacations, and the job helped pay for her first year of college. During college she would do many other jobs: She served coffee in the student union (学生会), was a hotel maid and even made maps for the US Forest Service. But selling books was one of the most satisfying jobs.
One day a woman came into the bookstore and asked Ann for books on cancer. The woman seemed anxious. Ann showed her practically everything they had and found other books they could order. The woman left the store less worried, and Ann has always remembered the pride she felt in having helped her customer.
Years later, as a television reporter in Los Angeles, Ann heard about a child who was born with problems with his fingers and his hand. His family could not afford a surgical (外科的) operation, and the boy lived in shame, hiding his hand in his pocket all the time.Ann persuaded her boss to let her do the story. After the story was broadcast, a doctor and a nurse called, offering to perform the surgical operation for free.Ann visited the boy in the recovery room after the operation. The first thing the boy did was to hold up his repaired hand and say "Thank you." What a sweet sense of satisfaction Ann Curry felt!At McCarley’s bookstore, Ann always sensed she was working for the customers, not the store. Today it’s the same. NBC News pays her, but she feels as if she works for the people who watch the programs, helping them make sense of the world.