WASHINGTON (AP) _ Becky Adler is only 17, but she has talked to a teen-ager who is worried about contracting AIDS from her college boyfriend and a man who's afraid his sexual past may have led to his pregnant wife being infected.

Adler, a high school senior, spoke with those people while taking calls on the ''Teen AIDS Hotline,'' which is staffed by teen-agers for teen-agers in the greater Washington, D.C., area. She said the line received 4,100 calls last month.

''If there is such a thing as a high-risk group, it is teen America. And we at the Teen AIDS Hotline are working to save our generation,'' Adler told the House Select Committee on Children, Youth and Families at a hearing Thursday on teen-agers and AIDS.

Adler said other AIDS efforts in her suburban Washington community, all financed by contributions and candy sales, include weekend teen and family conferences on AIDS sponsored by churches and synagogues; AIDS nights for parents, teachers and students; a video discussion guide for parents, teachers and clergy; and ''The AIDS Movie,'' the first AIDS prevention film for adolescents.

''Teach your children the facts on AIDS and how they can protect themselves,'' Adler urged the committee. ''Then help us show other teens throughout the country how they can stop the AIDS epidemic in their communities.''

The hearing, chaired by Rep. George Miller, D-Calif., examined the AIDS risk to teen-agers. Many witnesses noted that teen-agers are particularly vulnerable because they are prone to experimentation with sex, drugs and alternative lifestyles.

Surgeon General C. Everett Koop said younger children should be taught by their parents and teachers to abstain from sexual relations until they are ready for marriage. ''It's entirely possible to raise a whole generation of adolescents who will be abstinent until monogamous,'' he told the committee.

But Koop said during questioning that youngsters who have reached puberty must be taught that condoms used correctly can help protect them from AIDS. He said 70 percent of teen-agers are sexually active and it is not realistic to expect their behavior to change.

''If you tell that 70 percent to just say no, they laugh. And if they try to say no, they find it very difficult,'' Koop said. ''I was talking to some teen-agers about long-term monogamy and this one girl said, 'How long? A semester?'''

Under questioning by committee members, Koop predicted AIDS testing of surgical patients soon would be a widespread practice and he said health officials should know within several months whether there will be an explosion of AIDS among heterosexuals.

The surgeon general said there will be an increased demand for surgical- patie nt AIDS testing by doctors and nurses in danger of contracting the virus through pin pricks, knife cuts and other accidents in the operating room.

''The day is not far off when the testing of surgical patients in hospitals becomes much more routine,'' he said.

Koop said he could not tell lawmakers ''if we are standing on the threshhold of a heterosexual explosion of AIDS.'' But he added, ''We will know in six to eight months.''

Heterosexuals now account for only 4 percent of AIDS cases in the United States.

Miller, Koop and other witnesses said the low number of teen-agers diagnosed with AIDS - 148 as of June 8 - is misleading because 7,500 people between 20 and 29 have AIDS and may have contracted the virus during their teen-age years.

Koop didn't mention condoms in his prepared statement to the committee, prompting some lawmakers to wonder if Education Secretary William Bennett and others who advocate an abstinence-only approach had influenced his views.

Koop said he has not altered his message at all. He said he always has advocated abstinence first, monogamy second and - failing those two options - the use of condoms, far from failsafe but the only protection available.

Asked why there is so much political division on a matter of life and death, Koop answered: ''If we were dealing with a disease that only bankers with bald heads got, we wouldn't have any problem at all.''

The chief victims of acquired immune deficiency syndrome, a contagious disease that attacks the body's immune system, have been homosexual men and intravenous drug users.

As of May 25, AIDS had been diagnosed in 35,980 Americans, of whom more than half, or 20,798, have died since 1979, according to the federal Centers for Disease Control. No one is known to have recovered from AIDS.