阅读填空 先通读下面的短文，然后根据短文内容，在文章后表格的空格内填入一个最恰当的单词。所填单词必须写在答题卡对应题号的横线上。每个空格只能填一个单词。

    A study shows that one million lives might be saved each year if people wash their hands with soap(肥皂) often. It also says that hand-washing with soap could be among the best ways to reduce diseases. Doctors say many diseases can be prevented from spreading by hand-washing. These include the common cold, influenza(流行感冒), hepatitis(肝炎), infectious diarrhea(腹泻) and so on.

    Doctors say you are easy to catch a cold by touching your nose or eyes after someone nearby has sneezed or coughed. Another reason to catch a disease is to eat food prepared by someone whose hands were not clean.

    They also say that hand-washing is especially important before and after preparing food, before eating and after using the toilet, after touching money and sneezing or coughing. The most helpful way is to wash them together while using soap and warm water. You do not have to use special soap. Be sure to wash all areas of the hands for about ten to fifteen seconds.

Title : Basic Knowledge of hand-washing

一物体在与初速度相反的恒力作用下作匀减速直线运动，v₀=20m/s，加速度大小为5m/s²，求：

小星家的太阳能热水器，水箱容积是200L．小星进行了一次观察活动：某天早上，他用温度计测得自来水的温度为20℃，然后给热水器水箱送满水，中午时“温度传感器”显示水箱中的水温为45℃．请你求解下列问题：
（1）水吸收的热量【c_水=4.2×10³J／（kg·℃）】
（2）如果水吸收的这些热量，由燃烧煤气来提供，而煤气灶的效率为40％，求至少需要燃烧多少千克煤气（煤气的热值为q=4.2×10⁷J／kg）