'A 1984 survey found an additional 2,500 miles to this barrier, now totaling 6,200 miles long'
the Great Wall of China
ENGINEERING: A 1984 survey found an additional 2,500 miles to this barrier, now totaling 6,200 miles long
A 1984 survey found an additional 2,500 miles to this barrier, now totaling 6,200 miles long
A 1984 survey found an additional 2,500 miles to this barrier, now totaling 6,200 miles long
ENGINEERING
the Great Wall of China
ENGINEERING