The Aztecs constructed chinampas .

Because the Chinampas helped agricultural and territorial expansion that, through a kind of rafts covered with soil, served to cultivate flowers and vegetables, as well as to expand the territory on the surface of lakes and lagoons of the Valley of Mexico; making Mexico-Tenochtitlan a floating city. They used them for agriculture and gain ground in the lake waters.

byzantine empire is the answer i think you are looking for.

hope this : )

#2 the answer is d

#3 the answer is a

#4 the answer is b