大学英语：It was not until many centuries later that

　　1. It was not until many centuries later that the ancient Greeks placed the science of map-making on a sound footing. 这是一个典型的强调句型，not until many centuries later是被强调的成分。

　　2. Flattened 平面的

　　3. Given(考虑到) the state of knowledge of those times， he got things wrong.

　　4. His estimate of China and the Atlantic Ocean was far from being accurate.(动名词作介词宾语，表示一点不准确)

　　5. Move(v.移动)-immovable(adj.固定不变的);use(v.使用)-useless(adj.无用的)

　　6. Assume 假定