Each of the words at the bottom can either go before or after a word on the blank to create ten common two-word phrases. Some words have more than one possible placement, but there is only one arrangement which uses all ten words.
The phrases are:
WORLD PEACE / PEACE TREATY
AIR STRIKE / STRIKE OUT
TAP WATER / WATER WHEEL
EMPTY NEST/ NEST EGG
ROCKING HORSE / HORSE RACE
Reading the first letters of each answer, going down the columns, gives WATER TOWER, which is the answer.