The nutrients in _____falls into the ocean quickly become available to other living creatures.

His promise _____ he would give away half of the year’s income to the disabled turned out a lie, _____ made the public feel cheated.

I think this is the very work that we must finish ____ her.

. ________ when the boulders suddenly disappeared.

--- Whom should I give this dictionary to? --- You may give it to ______.