| bubble |
a ball of air or other gas inside another substance. |
| center |
the area or part of something that forms the middle. |
| course |
the direction or way along which something moves. |
| drill |
a tool used to make holes in wood, metal, and other materials. |
| during |
all through a certain period of time. |
| gas |
a form of matter that is neither liquid nor solid. Oxygen is an example of a gas. |
| goal |
a result or end that a person wants and works for; aim or purpose. |
| key |
a metal object cut in a special way so it can open or close locks. |
| section |
a part that is different or apart from the whole. |
| size |
how big or small an object is. |
| sneak |
to move quietly and in a sly way. |
| tricky |
using or marked by tricks or lies. |
| unfair |
against what is right or just. |
| vanish |
to disappear suddenly from sight. |
| worried |
feeling trouble or anxiety about something that might happen. |