MATTER AND MATERIALS. PROPERTIES OF MATTER.
Gap-fill exercise (by Juan Luis Serrano Pedrosa).
Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!
USE THESE WORDS.
space
matter
mass
volume
two