Questions 1 to 5 are based on the following passage. When the water source is farther than one kilometer, per capita consumption drops to around five liters (a little more than a gallon) per day. With so little water, basic hygiene (卫生) is frequently compromised. The report estimates that households getting water from taps may use 30 times more water for child hygiene compared with those who have to collect water from a communal source. This brings the added burden of illness to families already living in poverty. Infectious waterborne diseases such as diarrhea, typhoid, and cholera are responsible for 80 percent of illnesses and deaths in the developing world, many of them children. One child dies every eight seconds from a waterborne disease; 15 million children a year. Women and female children who have to travel to collect water pay a high cost. Less time is available for caring for children, preparing food, or pursuing alternate economic activities. In some regions the women and girls must travel through unsafe areas and are vulnerable to attack. Families in many cases must forgo sending their girls to school, perpetuating the grinding cycle of illiteracy and poverty. The amount of water a person needs can vary; a person doing manual labor in the tropics will need more water than someone sitting at a computer in a temperate zone. WHO suggests 2 to 4.5 liters (0.5 to 1 gallon) a day for drinking, and another 4 liters (1 gallon) for cooking and food preparation are the bottom-line limits for survival. This doesn't take into account water needs for growing food.