Fill in the Blanks UNIT 5 READING 9THOnline version Students have to complete the reading with the right words by Douglas Rivera 1 formed looks eroded was be seen viewed created was is was thought The Eye of the Sahara is a colorful rock structure in Mauritania , in western Africa . When it from above , the circular , dome - like structure like a giant bull's eye . people once that it by a meteor that struck the earth many years ago . However , it in fact from uplifted rock . This rock by wind over many years . The structure is 40 kilometers wide and can by astronauts from space .