Question

what is not true about the great wall of china?
a. it includes watchtowers as signal stations.
b. it is a 1,500 - mile - long wall.
c. it was begun during the qin dynasty.
d. it was constructed with concrete arches of polygonal voussoirs.

Explanation:

To determine what is NOT true about the Great Wall of China, we analyze each option:

• Option a: Watchtowers as signal stations is true (used for signaling via smoke/fire).
• Option b: The Great Wall is over 13,000 miles long, but a 1,500 - mile - long section or description could be contextually true in some references (or the question might have a specific context where this is considered true, while other options are more clearly false).
• Option c: Construction of the Great Wall began during the Qin Dynasty (Qin Shi Huang unified and connected earlier walls) is true.
• Option d: The Great Wall was built with materials like bricks, tamped earth, stone, etc., not concrete arches of polygonal voussoirs (concrete - like materials and such architectural features are not part of the original Great Wall construction). So this statement is NOT true.

Answer:

d. It was constructed with concrete arches of polygonal voussoirs.