1. He is building the house(сейчас); He builds the house(всегда,обычно); He will built the house(в будующем); He built the house.(в 2.The flood is destroying this city;The flood destroys this city;The flood will have destroyed;The flood had destroyed. Порядок времён такой же,как и в первом случае.
2.The flood is destroying this city;The flood destroys this city;The flood will have destroyed;The flood had destroyed.
Порядок времён такой же,как и в первом случае.