阅读下面短文，根据短文内容，在回答所提问题的句子中填上恰当的词。每空一词。

　　EVERYTHING has two sides. One side of SARS is already clear. It is a deadly disease, which causes fear. There were 2,601 cases(病例) recorded on the Chinese mainland on April 24, according to government report. 115 people have died and numbers keep rising.

　　But, there is another side.

　　SARS is a reminder(提醒)of how fragile life can be. Suddenly, it's not just the old people who are thinking about death. Everyone now realizes there might not always be a tomorrow.

　　Wang Xinying, a student in Taiyuan, Shanxi Province came into contect(接触) with a suspected(疑似) SARS patient in mid-April. He was told to stay at home for at least two weeks. “Watching TV about more and more SARS patients dying, I never knew that death could be so close. Life is valuable(珍贵的) and I'm going to treasure (珍惜) every single day,” he said.

　　SARS teaches people to be grateful, both for their own lives and for others. Doctors and nurses, for example, have to spend all their time with infected(被感染的) patients. As a result, more than one fifth of SARS cases in China are medical workers.

Xu Bing, a student of Beijing No. 5 Middle School wants to be a doctor in the future. “Although they certainly know the dangers, doctors and nurses kept working hard on saving people's lives. I'm deeply moved by what they have done. I think they are real heroes,” he said.

　　SARS also teaches sympathy(同情). The past few weeks have been terrible for Chinese people. But there are far worse things than SARS in this world, such as war, earthquakes and robberies. Think of the Iraqis, who have been living terrible lives for 20 years. Think of how the Americans felt on 9/11.

　　And finally, SARS offers the chance to grow. All different kinds of people and the governments are joining together to work in this difficult tine. When this passes, China and its people, will have learned great lessons.

1．What does “Everyone now realizes there might not always be a tomorrow?” mean?

It means life is easy to ________ and we must ________ our life.

2．How long was Wang Xinying told to stay at home?

He was told to stay at home for about ________ a ________.

3．Why can medical workers be easily infected?

Because they have to be with infected patients ________ and ________.

4．What do we learn in the difficult time?

We learn nothing is difficult if we ________ ________.