Answer:
Gravity
Explanation:
The hummingbird beats its wings to hover as it is pushing against the force gravity to hover. E.g. Without gravity an apple would never fall as it is the force that causes it to do so.
will be
cleans
gets
donated
flood
fail
boils
wastes
recycled
use
I believe you're looking for the third down option starting with "Monticello was built"
