You just did use a sentence.
Answer:
feeding
Explanation:
the present tense term for feed is feeding
hope that helped.
You can re-arrange your sentence in this way:
In order to identify the development of tornadoes, few required conditions can be described.
Slowly, eventually, lonely, and i think new
A: terribly: modifies old, an adjective
B: very smart: very modifies smart, an adjective
C; extremely modifies "slow", an adjective again
D: quickly modifies "hid" a verb - this is the correct answer!