In one sentence, describe what the following article is about: Nicotine can quickly cause yellowing of your teeth. This occurs whether you smoke cigarettes or use chewing tobacco. Nicotine and tar settle into the very small cracks in the enamel of your teeth, and cause discoloration. It has been shown that nicotine helps the process of plaque formation, which leads to a faster deposit of tartar and can cause bad breath. In addition to discoloration, nicotine use can cause other physical problems for your teeth and gums. You may be prone to increased cavities, gum disease, and certain types of oral cancer. All of these ailments can decrease the healthy appearance of your teeth. One way to prevent the yellowing of teeth is to make sure that you are taking excellent care of your mouth. Good oral hygiene includes brushing your teeth twice a day. You should use a whitening toothpaste in combination with a soft-bristled tooth brush. Brush firmly but gently at least twice a day. Flossing is also important. You should make sure to use dental floss once a day. This can remove buildup of foreign material between your teeth. The best way to put a stop to the yellowing of your teeth is to quit using nicotine. Quitting is a very difficult process, but there are many methods you can try. Consider using cessation aids, such as chewing gum or nicotine patches. There are also prescription medications to help with your addition. Ask your doctor for help in choosing a safe and effective method.
Summary: Learn about discoloration. Know the risks of disease. Practice good oral hygiene. Try to quit.

In one sentence, describe what the following article is about: It's the blue icon with a white "F" on your home screen or in the app drawer. If you haven't yet signed in, enter your login information and tap Sign In. If any of your Facebook posts were set to Public or Friends of Friends, this method will convert them to Friends Only. Though the posts will not be deleted, they'll only be visible to people you're friends with on Facebook. It's at the top-right corner of the screen. If you see "Account Settings," you can skip this step. " Your past Public or Friends of Friends posts are now set to Friends Only.
Summary: Open Facebook. Tap . Scroll down and tap Settings. Tap Account Settings. Tap Privacy. Select "Limit the audience for posts you've shared with Friends of Friends or Public? Tap Limit Old Posts. Tap Confirm.

In one sentence, describe what the following article is about: Do whichever is comfortable.
Summary:
Dribble with your left or right hand.