<u>Answer:</u>
Comfortable
<u>Explanation:</u>
One type of the adjectives is predicate adjective. A predicate adjective is an adjective which follows a linking verb and modifies or refers back to the main subject of that linking verb.
It usually is used just before the noun it modies.
Here in this example:
'Penguins seem comfortable in the coolest habitats', comfortable is the predicate adjective which follows the linking verb 'seem' and modifies the noun.
If I understand correctly, they are words that are used to compare things.
The man had jumped from a plane but his parachute had failed to open. It is the unopened package.