Please I need help with 7 and 8

The Eastern part of the Roman Empire is called as Byzantine Empire.

Greatest contribution of the Byzantine Empire is preserving Greek and Roman culture.

Explanation:

When the Germans invaded in the 5th Century, the Western part of the Roman Empire fell apart. The Eastern part were able to withstand the fall and it came to be a continuation of the Roman Empire. It was called as the Byzantine Empire. Its capital city was Constantinople. The greatest contribution of the Empire was preserving Greek and Roman culture. When the Roman Empire fell in 476 AD, many documents, books and libraries were lost. The Byzantine Empire which was considered as the Roman empire to its people preserved the Greek and Roman Culture. Science, Ethics and Greek Philosophy thereby, became the foundation of the Western civilization.

The congress completes the diagram