When thinking about quitting... List all the reasons why you want to quit. Every night before going to bed, repeat one of the reasons 10 times. Decide surely that you want to quit. Try to avoid negative thoughts about how difficult it might be. Develop strong personal reasons in addition to your health and duties to others. For example, think all the time you waste taking cigarette breaks, rushing out to buy a pack, hunting a light, etc. Set a date for quitting--perhaps a special day like your birthday, or a holiday. If you smoke heavily at work, quit during your vacation. Make the date seriously, and don't let anything change it. Begin to prepare yourself physically: start a modest exercise, drink more water, get plenty of rest. Immediately after quitting... The first few days after you quit, spend as much free time as possible in places where smoking is forbidden, e.g. libraries, museums, theatres, department stores, etc. Drink large quantities of water and fruit juice. Try to avoid wine, coffee, and other drinks, which remind you of cigarette smoking. Start a conversation with someone instead of asking for a match for a cigarette. If you miss the sensation of having a cigarette in your hand, play with something else--a pencil, a pen, or a ruler. If you miss having something in your mouth, try toothpicks or a fake cigarette. From the passage, we know smokers   _  .
spend a lot of time breaking the habit of smoking have to stop to smoke from time to time had better quit smoking during their holiday start a modest exercise every day