A、When we feel relaxed. B、When we feel bored. C、When we are hungry enough. D、When we can be consistent. DDr．Smith提到，一天当中健身的最好的时间

Moderator:
    Hello, ladies and gentlemen. It gives me great pleasure to introduce our speaker for today’s lecture, Dr. Brick Smith. Dr. Smith, professor of medicine at Washington University,(16)has written numerous articles and books on the issue about keeping fit as well as a good figure, which has benefited those who are overweight and eager to lose weight.
Dr. Smith:
    Thank you for that introduction. I feel happy to meet you here. Want to slim down, tone up, and get healthier in just a month? Follow these simple fitness tips. You’ll feel better in no time.
    Eat before you get to a party. A small meal before you go makes it easier to pass on fattening hors d’oeuvres.
    Set a reasonable goal and time line for your weight loss. Using a healthy system, you should only be losing one to two pounds a week.(17)So don’t push yourself too hard, or you could do more harm than good.
    Know that you can do a lot in a month. Work out four days a week, doing 30 minutes of cardio like jogging, biking, walking and so on, or work on your abs every day, plus two days of upper body and two days of lower body work.
    Make the most of your time at the gym: Any kind of cardio activity, ideally one that incorporates the upper and lower body at the same time, is great. For example, there’s a machine called the Versa Climber, which is a vertical climbing machine—it’s like a StairMaster with a feature that incorporates the upper body too.
     (18)The best time of day to work out is whenever you feel best’and when you’re most likely to be consistent. If you’re a morning person, hit the gym before work. But if you’ve ever considered hanging a sign at your desk that says "Don’t talk to me ’til I’ve finished my coffee," an evening workout may be better for you.
     (19)Drink only water while working out. If you must drink a sports drink, dilute it with one part drink to three parts water. If you drink sports drinks on their own, they’re so concentrated that any vitamins or electrolytes you think you’re benefiting from are actually going straight through you.
    Consider using a heart-rate monitor, especially when you’re on a crash course to fitness. It’ll keep you within your target heart rate!
    Carry snacks with you. With so many things to do, you’ll likely be caught without time to eat properly.
    If you tote around an apple, a banana, or an energy bar, you’ll be less apt to scarf down a bag of chips in between errands.
    Thanks for listening!
16. What does the introduction say about Dr. Smith s articles and books?
17. What will happen if we push ourselves too hard to lose weight?
18. What is the best time of day to work out?
19. What should we do with the drink while working out?