This statement is wrong.
The second part of the sentence is actually correct - the one describing what ziggurats are. However, the first part is incorrect - Sumerians were not monotheists. Monotheists believe in one god - for example, Christianity is a monotheistic religion. But Sumerians were polytheists - this means that they believed in many gods, such as Enlil, Enki, Nergal, etc.
European imperialism in the 19th century was motivated by the desire of acquiring raw materials for their industries. Other motives were for power and territory expansion. In the 19th century, power can be seen through how many colonies were under a European nation. since this also entails to greater economic and political power.
He promised to solve Italy's Economic problems.