Vocabulary Practice

4. a fuel that is made from living things or their waste
6. used when something is not certain
9. without any doubt
10. a condition or situation that causes problems, especially one that causes something or someone to be less successful than other things or people
12. (the use of) a new idea or method
13. the process of finding information, a place, or an object, especially for the first time, or the thing that is found

1. used to mean that something is very likely
2. an illness, injury, or condition that makes it difficult for someone to do the things that other people do
3. a helpful or good effect, or something intended to help
5. a worried or nervous feeling about something, or something that makes you feel worried
7. relating to science, or using the organized methods of science
8. a movement of the hands, arms, or head, etc. to express an idea or feeling
11. a condition giving a greater chance of success