Where are the statement options?
Byzantium/Constantinople was conquered in 1451, but the empire continued to decline starting around the 18th or 19th centuries. It officially died in WWI. As for how long it was a major threat to Europe, the empire's prime was the 16th century, under Suleiman the Magnificent.
I'm not sure if you made a typo or not but in the current context I can only see negligible being relevant.
Answer: Central America is a land bridge connecting the North and South American continents, with the Pacific Ocean to its west and the Caribbean Sea to its east. A central mountain chain dominates the interior from Mexico to Panama. The coastal plains of Central America have tropical and humid type A climates.
Explanation:
Tang Dynasty was able to strengthen China thru the efforts of its Tang Taizong and Empress Wu in which the former brought back China's government and the latter empowered women. The Song dynasty continued the good governance and elevated the military system thru systematized testing.
