题目内容：
The Drink Your Body Needs Most1．Our bodies are estimated to be about 60%to 70%water．Blood is mostly water．and our muscles，lungs，and brain all contain a lot of water．Water is needed to regulate body temperature and to provide the means for nutrients(滋养物)to travel to all our organs． Water also transports oxygen to our cells，removes waste，and protects our joints and organs．
2．We lose water through urination(排尿)，respiration(呼吸)，and by sweating．If you are very active，you lose more water than if you do not take much exercise．Symptoms of mild dehydration(脱水)include chronic pains in joints and muscles，lower back pain． headaches，and constipation(便秘)．A strong smell to your urine，along with a yellow color indicates that you are not getting enough water．Thirst is all obvious sign of dehydration and in fact，you need water long before you feel thirsty．
3．A good rule of thumb(好的做法)is to take your body weight in pounds and divide that number in half．That gives you the number of ounces(盎司)of water per day that you need．For example，if you weigh 160 pounds，you should drink at least 80 0unces of water per day．If you exercise you should drink another 80 ounce glass of water for every 20 minutes you are active．If you drink coffee or alcohol．you should add at least an equal amount of water．When you are traveling on an airplane，it is，good to have 8 0unces of water for every hour you are on board the plane．
4．It may be difficult to drink enough water on a busy day．Be sure you have water handy at all times by keeping a bottle for water with you when you are working，traveling，or exercising． If you get bored with plain water，add a bit of lemon for a touch of flavor．There are some brands of flavored water available，but some of them have sugar or artificial sweeteners that you don’t need．
根据以上内容，回答题。
Paragraph 1______. A．Ounces of Water Needed Per Day
B．Importance of Water
C．Composition of Water
D．Signs of Dehydration
E．Supply of Water
F．Necessity for Bringing a Bottle for Water
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