Read the definitions carefully and select the correct words.
1. to examine or think about something carefully, in order to understand it
2. a careful examination of something in order to understand it better
3. to do and complete a task
4. to say that something is definitely true
5. a statement, document etc that says that something is definitely true
6. to find information, a place or an object, especially for the first time
7. a fact or thing that someone finds out about, when it was not known about before
8. to be, or to be real
9. the state of existing
10. a scientific test done to find out how something reacts under certain conditions, or to find out if a particular idea is true
11. the act of travelling through a place in order to find out about it or find something such as oil or gold in it
12. to travel around an area in order to find out about it
13. to make, design, or think of a new type of thing
14. the action of inventing something, typically a process or device
15. before now or before a particular time
16. a machine that has been sent into space and goes around the Earth, moon etc, used for radio, television, and other electronic communication
17. knowledge about the world, especially based on examining, testing, and proving facts
18. about or related to science, or using its methods
19. someone who works or is trained in science
20. until now
21. having no holes or spaces inside
22. a vehicle that is able to travel in space