第 21 至 30 題為題組      Water makes up more than half of our body weight. To sustain this amount of fluid in our bodies, plainwater is considered our best choice, for it contains no sugar and no calories. Yet, is water always thehealthiest drink we can  21  ? Well, it depends on who and where we are, and what we’re doing.       Obviously, a physically  22  person with an outdoor job under the sun will need to drink morefluid than a desk-bound person who lives and works in an air-conditioned place. But there’s more to it thanthat. When a person sweats, he loses water and salt, so he needs to replace both. Replacing lost fluid withjust plain water means the body has too much water and not enough salt. To  23  things out, the bodywill get rid of water by producing urine. For this reason, milk can actually be more  24  than drinkingwater. Milk naturally contains salt and lactose, a sugar which the human body needs in small amounts tohelp stimulate water  25  . Coconut water, which contains salt and carbohydrates, is also morefunctional than water at restoring and maintaining a normal fluid  26  after exercise.      For the average person, however, water remains a very good  27  for keeping hydrated—if youknow how to drink it. The secret is: Never wait until the body is telling you you’re thirsty, since there mustalready have been significant changes in your body for it to eventually  28  your consciousness. Atthat point, it might be well past the best moment to take in fluid. Also, drinking a lot of liquid in one go cancause more water to  29  the body quickly and come out as urine. To  30  this, you need to drinkwater throughout the day to maintain your hydration levels.
【題組】 (AB) absorption (AC) active (AD) alert (AE) combat (BC) option(BD) effective (BE) even (CD) status (CE) pass through (DE) reach for