Even though very small amounts of each vitamin are enough for the needs of the body, the worry people have about vitamins has some reasons. And this has to do with their __1_     --- the food they take in. A person eating a good variety of food get all the vitamins now __2  ___ (know) to be needed.

The problem is that there are many people who don’t ___3_  __ foods wisely. So the answer ___4  ___ this question is: No extra ___5_ __ are needed, ___6   __ you eat proper foods. In fact, many of the vitamins cannot be ___7_ __（store） in the body, so when extra vitamins are taken in, the body simply gets rid of them. It is even ___8   ___ (harm) to put too much of certain vitamins into the body. This has been found to be ___9       (truth) of vitamin A and D, when ___10    ___ amounts are taken in.

什么是煤的自然堆积角？