Ⅰ. 根据句意及首字母或汉语提示完成单词(5分)
1. His brother joined the a______ in 2012.
2. Norman Bethune was a famous C______ doctor.
3. The doctor joined a m______ team to work in a village.
4. Now many poor people can get free t______ when they are ill.
5. Potato chips were______ (发明) by mistake.
