According to the text, how can some animals live under extreme weather conditions: too hot or too cold?

• Because they have learned to adapt to the easy conditions
• Because they have learned to adapt to the difficult conditions
• Because they are smart animals

The polar bear and the camel ...

• need special conditions to exist
• don't need any special conditions to exist
• can live in any kind of conditions

Why does the text mention the "tardigrade"?

• Because it is the "water bear".
• Because it is very small. 
• Because it has the capacity to handle very high temperatures. 
• Because water and oxygen are important to them.

The Dead Sea is...

• where some extremophiles live
• has very low levels of salt
• great to meditate

"Extremophiles" are...

• bigger than the tardigrades
• microscopic organisms
• living in rocks only

On page 79, the first paragraph says that Strain 121 has remarkable abilities to tolerate high temperatures. What is remarkable?

• unique
• common
• normal

On the other hand, Methanogens thrive under 18 m of Antarctic ice with no light or oxygen. What is thrive?

• to have a bad time
• to do well
• to suffer

Why are scientists so interested in these organisms? 

• Because they help us understand our purpose
• Because they help us understand how life might exist on other planets
• Because they want to know why they exist

Kevin Hard, an astrobiologist who works for NatGeo, says that the scientists want to know how a planet can be habitable. What does habitable mean?

• In good conditions to live there
• In bad conditions to live there
• It is a synonym of ability