A、Keep your elbows on the table. B、Keep your mouth open. C、Pick up your bowl. D、Slurp from the plate. C文章提到吃饭时端起碗碟是令人难以置信的粗鲁行为，故

One of the great things about traveling around the world is all of the wonderful food you get to try. (29) Watch yourself when you start to reach for that food, though, or you just might offend someone. When it comes to table manners, what works in one country doesn’t always go over in another.
     The United States has its own special dining customs that visitors should know about before sitting down to a meal. For example, (30) when food starts to arrive, you can’t just dig in. It’s considered rude to start eating before everyone at the table has received his or her meal.
     Once you start to chow down, it’s important to remember to keep your elbows off the table and keep your mouth closed as you chew.  Don’t lean over and slurp from the plate on the table either. Food must be transported from the dish to your mouth with a fork or a spoon. (31) Never pick up your bowl or plate as you eat because this is especially considered rude beyond all belief.
      It is also considered rude to pick between your teeth where others can see you. Some restaurants usually do not supply toothpicks, so it is sometimes hard to decide when to remove food stuck between the teeth.  It is usually best to excuse yourself and go to the bathroom.