Planets

They ____ that its rings consisted of billions of icy particles.

• to find

• find

• found

• to be found

They ____ that these rings are extremely thin - only 10 m (33 ft) thick.

• studied

• discovered

• experienced

• sympathized

And they ____ that some of the planet's small moons play an important part in controlling the orbits and spacing of the rings.

• learned

• made

• created

• explored

Where you found ____, you generally find life.

• lava

• water

• blood

• rock

Where can the ocean deeper than the one on Earth be found?

The world may have began on our _____.

__ has more water and deeper oceans than the Earth.

• Canada

• Mariana Trench

• Antarctica

• Europa

What are the 3 keystones to consider a planet habitable?

What are the key elements for life?

If they studied it the way we are able to today, they ________(be) amazed.