DEAR ABBY: My grandsons are 16, 18 and 20 years old, and they all have girlfriends. Each also has his own bedroom.

When I visit my son's house a few times each week, the boys are always in their bedrooms with their girlfriends -- with their doors closed, supposedly listening to music or watching a movie on television. My son and daughter-in-law are either in other rooms, or outside in their pool, and choose not to disturb them.

Abby, knowing teen-agers have raging hormones, I don't think this is a very good policy, but I don't feel it's my place to say anything.

My son and daughter-in-law's attitude is, "Get with it -- this is the '90s," -- whatever that's supposed to mean.

What do you make of this, Abby? -- OLD-FASHIONED GRANDPA

DEAR GRANDPA: I'm "old-fashioned," too. What goes on behind closed doors could be perfectly innocent, but I see no reason why your grandsons can't watch movies or listen to music with their doors open. Young people need some privacy, but too much of a good thing can result in temptations too intense to resist.

Talk to your son and daughter-in-law and share the wisdom of your years by suggesting an "open-door" policy.

DEAR ABBY: When I was in law school, I shared an apartment with three other graduate students who, like me, held part-time jobs and had little time, money, cooking ability or interest in preparing meals. Each of us got his own breakfast and we took turns preparing dinner -- which usually consisted of a canned vegetable, hamburger meat, a baked potato or the like -- and was barely edible. (I lost 25 pounds going through law school.) But no matter how poor the meal was, my roommate "Joe" invariably said, "That was a mighty fine dinner!"

One evening, when the meal I had prepared was even worse than usual and Joe had nevertheless complimented me, I asked, "Joe, you know that food was hardly fit for human consumption. Why do you always say it's good?"

"I come from a family of 11 children," Joe answered. "My mother would spend all afternoon in the kitchen preparing the evening meal. Then, one night when she called us to the table, there was only a plate at each place with a pile of hay on it. My father looked at it and asked her, 'Jessie, what is this hay doing on our plates?' Mother said, 'Oh, you noticed! This is the first time any of you have ever given any indication that you know what was on your plate!'"

"I vowed then and there," Joe added, "that I would always express my appreciation to the person who had prepared my meal."

Ever since then I have followed Joe's example. (Fortunately, I married a great cook as well as the best wife a man ever had.) -- PAUL M. BARNES, GREEN VALLEY, ARIZ.

DEAR PAUL: Thanks for a cute letter, and for the reminder that we should all take a moment to express gratitude for the things we take for granted. I hope you will share this column with your wife. I'm sure she'll appreciate the hearty endorsement.

Good advice for everyone -- teens to seniors -- is in "The Anger in All of Us and How to Deal With It." To order, send a business-sized, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby, Anger Booklet, P.O. Box 447, Mount Morris, Ill. 61054-0447. (Postage is included.)

DEAR ABBY: In the past you have encouraged people who are trying to kick their addiction to tobacco to "quit for a day" by participating in the Great American Smokeout. You have given many smokers the inspiration they needed to quit smoking.

This year, we at the American Cancer Society are urging all smokers to stop smoking, and stressing to young people the importance of not starting. Teens and pre-adolescents must be made to understand that there is nothing glamorous about smoking. Smoking and using smokeless tobacco products can, and will, kill them. Our message to kids is: Don't start using tobacco products of any kind!

Abby, please alert your readers to the Great American Smokeout again this year. Thank you for your continued dedication and help in the fight against cancer. -- JUNE K. ROBINSON, M.D., PRESIDENT, ILLINOIS DIVISION, AMERICAN CANCER SOCIETY

DEAR DR. ROBINSON: I'm pleased to announce that tomorrow, Nov. 21, 1996, will mark the American Cancer Society's 20th Annual Great American Smokeout.

DEAR READERS: The Smokeout is a one-day campaign to encourage smokers to quit smoking for 24 hours -- to prove that they can do it. Last year, more than 11 million smokers quit for the day -- that's a giant step in the right direction!

An estimated 450,000 Americans will die from smoking-related diseases in 1996. That means tobacco will claim 51 lives every hour in the United States. An estimated 158,700 of them will die from lung cancer. These numbers are staggering -- more than the combined number of people who will die in one year from alcohol, AIDS, crack, cocaine, murder and fire. The total exceeds the number of U.S. battle deaths in World War II, is eight times the number of those killed in Vietnam, and is 10 times the number who die annually in automobile accidents.

For years I have implored my young readers, "If you smoke, quit now. If you don't smoke, don't start." Unfortunately, today one in five teen-agers smokes, and the number of kids using tobacco is growing. More than 80 percent of smokers report that they started during their teens; every day another 3,000 get hooked. Now I'm urging: "Be smart -- don't start!"

There was a time not too long ago when lung cancer in women was relatively uncommon. However, if women continue to smoke at their current rate, it is estimated that early in the next century more women than men will die of lung cancer.

Does secondhand smoke affect non-smokers? You bet it does! According to a definitive report issued by the U.S. Environmental Protection Agency in 1993, secondhand smoke is a Class A carcinogen on a par with asbestos and radon. The report also showed that children of smokers are more prone to lung problems and allergies than children of non-smokers. Secondhand smoke is also a significant risk factor in Sudden Infant Death Syndrome (SIDS). Therefore, if you are an adult and you must smoke, don't smoke in the presence of children.

My readers tell me that while "cold turkey" is the most difficult, it is the most effective way to kick the habit. Those who need help or want more information about the effects of tobacco may call the local chapter of the American Cancer Society or 1-800-ACS-2345.

So, Dear Readers, if you're hooked on tobacco and have been saying, "One of these days, I'm going to quit," why not join the Great American Smokeout and quit tomorrow? It won't be easy, but it will be the best Thanksgiving gift you can give yourself, and those who love you.

For Abby's favorite family recipes, send a long, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby, Cookbooklet No. 1, P.O. Box 447, Mount Morris, Ill. 61054-0447. (Postage is included.)

DEAR ABBY: During the holidays, many communities sponsor programs in which people buy new toys or clothes for needy children. Many of these children come from homes where there are no books.

An ongoing cycle of illiteracy haunts children on the edges of poverty. When teachers ask their students to bring a favorite book to class to share, these children show up with an advertisement or a coupon book because they have no books at home.

Abby, please help these children learn to love books and reading. If your readers are buying toys or clothes for needy children, please ask them to consider tucking in one or two children's books. -- D.W. IN RENO, NEV.

DEAR D.W.: I'm sure many readers will agree it's a great idea. Books make excellent gifts.

DEAR ABBY: Whoever gave you the misinformation regarding dinner table protocol that you passed on to "Serious in Boston" needs retraining themselves.

I'm a former embassy butler, and please know that the signal conveyed to a trained server, as you described the positioning of cutlery and plate (knife and fork together diagonally across the upper right rim of the plate), would be that the diner would appreciate being offered another helping.

To indicate that you are finished and wish the plate removed, the cutlery should be placed straight upon the plate, perpendicular to the diner, as clock hands at half past six, with the knife upon the right with the blade edge toward the fork.

If you are being attended by properly trained staff, it can avoid embarrassment to know what signals you are sending to the server.

Most sincerely at your service ... RUGGLES OF RED GAP

DEAR RUGGLES: Thank you for speaking up. Concerned that I had misled my readers, I consulted several more etiquette books. "The New Emily Post's Etiquette," by Elizabeth L. Post, states: "When you have finished the main course, the knife and fork are placed beside each other on the dinner plate DIAGONALLY FROM UPPER LEFT TO LOWER RIGHT. (Emphasis mine.) The handles extend slightly over the edge of the plate."

"The Amy Vanderbilt Complete Book of Etiquette Entirely Rewritten and Updated," by Nancy Tuckerman and Nancy Dunnan, says, "Put your fork and knife across the center of your plate ON A DIAGONAL SLANT when you have finished eating."

Letitia Baldrige, whom I telephoned, told me that the flatware should be placed on the right rim of the plate, straight up and down -- not diagonally.

I can only conclude that the best way to signal that you have finished eating is to speak up and tell the server that you would like your plate removed.

Read on for a thought-provoking letter from a reader who offers a different perspective:

DEAR ABBY: While I have never written to you before, the letter from "Serious in Boston" -- whose English-born and reared ladyfriend criticized him for pushing his plate to the center of the table when he had finished eating -- really got under my skin.

In view of what is going on in this world today, just how important is it to place the knife and fork in a certain way in order to signal the server to remove your plate? Give me a break! I say, "Tell the lady to go back to England and eat with the Queen!"

I get a lot more upset about how few people have food to put on their plates, plates to put on their tables and roofs over their heads. -- MARY A. SLOAN, SACRAMENTO, CALIF.

To order "How to Write Letters for All Occasions," send a business-sized, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby, Letter Booklet, P.O. Box 447, Mount Morris, Ill. 61054-0447. (Postage is included.)