1. They walked along a ______(泥泞的) road and there was a lot of mud on the road.
2. They soon overcame the language ______ (障碍）.
3. My ______ (同事）has got rid of the habit of smoking.
4. ______ (潮湿的) wood doesn’t burn well.
5. ______ (细菌) is the plural form (复数形式) of bacterium.
6. The teaching ______ (全体员工) of this school is/are excellent.
