Jonathan wrote the following research question, but he wants to improve it. When did the Roman Empire fall?

Which revision improves Jonathan’s research question?

a. How long did it take for the Roman Empire to fall?
b. How did internal disputes contribute to the fall of the Roman Empire?
c. What territory was held by the Roman Empire when it finally fell?
d. Why did the Roman Empire fall after being so strong for so long?

yh it is right

explanation:

b and d

explanation:

comfortable

explanation:

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.