Of all the things we eat and drink，water is the1important.The human body can go2 food for a long time，but two3three days without water could make people4.
   A lot of people don't understand how5water the human body needs6well and many people don't drink enough，esecially in7weather. Most people drink8they are thirsty but in fact they need more water，expecially when they take9.A man's body is 65 to 75 percent of10. If we don't have enough water. We fell tired and may become ill.

下列词语中划线字的读音完全正确的一项是（   ）  

-- What are you____ (do)?

-- I ____ ____a letter. (write)