题目内容：

阅读下面短文, 根据短文内容完成句子。

Chris is not a traditional explorer（探险者）—he usually works in an office for a large organization（机构）. But his job can sometimes be just as exciting and dangerous as being an explorer.

Chris works for MSF, an organization also known as Doctors Without Borders（无国界医生）. MSF sends trained doctors all over the world to help people after a war or a disaster（灾难）. Chris is a doctor from France who has travelled to many places to help the people.

At the moment, there are over 27,000 trained medical members taking part in MSF projects and tasks. The organization received the Nobel Peace Prize in 1999. All kinds of doctors can volunteer for MSF. They need to be prepared to go almost anywhere in the world. When MSF accepts a doctor for a task, he or she has to go for at least six months. When doctors have completed a few tasks, they might be sent on another task, such as an earthquake.

But why would a doctor leave a comfortable life and a good salary to join MSF? According to Chris, the experience you gain is a great help in your career. Besides, just like the explorers of the past, you need to keep an open mind and learn to get on well with the people you meet. Most importantly, at the end of each task, you have made a real difference to people's lives.

1.Chris usually works in an office for ________.

2.MSF sends trained doctors all over the world to help people in trouble ________.

3.There are ________ trained medical members taking part in MSF projects and tasks.

4.As a volunteer doctor for MSF, he or she has to go for ________.

5.All the volunteers’jobs are important because they ________.