| behind |
in or at the back of; on the other side of. |
| diagram |
a drawing or plan that shows the parts of something or how the parts work together. |
| explore |
to travel in order to discover or search for something. |
| hero |
a person who has courage and who is a model for others. |
| invite |
to ask in a polite way to go somewhere or do something. |
| know |
to have information in your mind that comes from what you have learned or can see. |
| mass |
a large amount or number. |
| pain |
bad or terrible feeling in your body that is usually caused by injury or illness. |
| pair |
two things that are the same and are used together. |
| photo |
a short form of photograph. |
| poem |
a piece of writing different from ordinary writing in its special form, rhythm, and beautiful or interesting language. Poems are often short and express feelings. They sometimes use words that rhyme. |
| river |
a large natural stream of water that flows toward a lake, ocean, or other larger body of water. |
| stamp |
to push down against a surface with a hard fast motion. |
| vacuum |
a space or container in which there is no air or from which most of the air has been removed. |
| zone |
an area that is separate or different from other areas because of a particular environment, use, or some other special quality. |