A、The speakers don’t know the problems with Mark and Tim. B、They are talking about how to make their sons live a healthy life. C

W: I am so worded about Mark these days. Ever since he moved into his own apartment he’s been losing weight. He doesn’t look well at all.
M: He really should try to gain some weight. He’s probably not eating enough. Have you talked to him about it?
W: Yes, but well...Noticed Tim?
M: Oh, he has us worried, too. He has really been getting much too fat. He needs to lose about 70 pounds now.
W: Yeah. That’s a lot of weight to lose. But if he keeps eating too much cake and candy, there’s no way to...
M: Well, he should go on a diet. Eat more vegetables and fruits, less sweets and meat.
W: I keep telling him to, but he doesn’t listen to me.
M: Maybe Mark should talk to him.
W: Maybe. Did I tell you that Mark needs two packs of cigarettes a day?
M: Hmmm, that’s probably why he’s so thin. You know, if he gave up, he would gain weight. I know he would. I put on a lot of weight when I stopped years ago.
W: Yes, we should try to persuade him to stop. But Tim has another problem—even worse. He drinks soda. Soda for lunch, dinner, after dinner.
M: Well, Mark never likes that. I think Tim does need exercise.
W: But he’s so lazy, never plays any sports. And whenever I tell him to take a walk, he just gets angry.
M: Mark doesn’t exercise, either. He just works so hard. No time to exercise or relax. I wish he could find a nice girlfriend to relax and have fun with.
W: Tim has a girlfriend. But she can’t cook!
M: Well, they’re 30-year-old boys, and they just don’t think they need our advice anymore.