介绍:
Task 6:
In the lecture, the professor explains two reasons why Roman city grew larger than the other ancient cities which are generally small and located on one side of the river.
The first reason is about the advanced technology the Romans invented. For instance, they invented special building materials, like a kind of concrete which becomes harder in the water, and this makes new structure possible, such as the bridge with higher quality which can cross the river. So the city can be built on both sides.
Secondly, Romans found an improved way to move fresh and clean water. They built a structure named "aqueduct", which are series of open channels bringing melting ice water from high mountains to people in the city. They are so well designed and constructed that even locations far from the river could have access to the fresh water. This helps a lot with the city expansion.
