【简答题】The human body is a living machine, and, like all machines, it needs "fuel" ( 燃料 ) to supply it with energy. This is provided by the food we eat. But how much do we need to stay healthy? The energy va...
【简答题】In the body part, the first paragraph we often ______________; the second paragraph we can write _________; the last paragraph usually _____________. (use the correct form of the word)