Chọn một đáp án trong số A, B, C hoặc D điền vào mỗi chỗ trống để hoàn thành đoạn văn sau. Today our (36)..... of food and what it does for our bodies is far more advanced than that of the ancient. Now we know (37) vitamins and how each kind of vitamins helps in the growth of a particular part of our bodies. There are on the market all kinds of vitamin pills one can take to make up for one's lack of certain important things (38) are needed for normal health. Of course, if we eat well and properly, the food that we eat will take care of our bodies without these pills. Just take vitamin pills if our doctor tells us that our bodies are short of something that (39)..... by them. Generally speaking, everything that we eat does some good to our bodies, but if we eat too much of one kind of food and pay no (40)..... to others, we may have too much of one kind of chemical substance and not enough of others. Then, we may be in trouble. Therefore the best advice about what to eat is that we should eat all kinds of food but never too much of any 36. A. knowledge B. know C. knowledgeable D. knowledgeably 37. A. in B. for C. about D. on 38. A. who B. which C. whom D. whose 39. A. can supply C can be supplied D. supplied 40. A. attraction B. action C. vision D. attention