认真阅读下面短文，并根据所读内容在文章后表格中的空格里填入恰当的单词。注意：每空一词。

     Many people believe they are supposed to drink eight glasses of water a day, or about two liters (升).

Why? Because that is the amount of water they have been told all their life. But a recent report offers some

different advice. Experts suggest people should obey their bodies: they should drink as much water as they

feel like drinking. The report says most healthy people meet their daily needs for liquid by letting thirst be

their guide.

     The report is from the Institute of Medicine, which provides scientific and technical advice to the

government and the public. The report contains some general suggestions. It says women should get about

2.7 liters of water daily and men about 3.7 liters. But wait-in each case, that is more than eight glasses.

     There is one important difference. The report does not tell people how many glasses of water are needed

to meet these guidelines. This is because the daily water requirement can include the water content in foods. 

     As you might expect, the Institute of Medicine says people need to drink more water when they are

physically active. The same is true of those who live in hot climates. Depending on heat and activity, people

could need twice as much water as others do.

                            How much water people should (1) _______ every day