Use of English PRO

It (0) SURELY (SURE) came from outer space (most of it arrived on Earth by meteorite), and you can still see it there in the visors of astronauts' helmets (it filters out (1) ............ (HARM) infrared rays). It can be found on every continent on the planet and it is thought that 80% of it is still buried deep (2) ............ (GROUND). And it's not only found on land: 25 tons of it float in every (3) ............ (CUBE) mile of sea water. Yet, despite being found in so many places, there is hardly any of it around. (4) ............ (AMAZE), if you compressed all of it together you would be unable to fill more than three Olympic-size swimming pools. It is a vital component of certain electronic products, such as mobile phones, GPS systems and computer systems, and it is (5) ............ (VALUE) in aerospace engineering and space aviation. Back here on Earth, it has been used by dentists since 700 BC to mend (6) ............ (BREAK) teeth. Scientists have discovered traces of it in our blood and in the dust at the side of the road. You can even eat it. Its name is derived from the Latin word for `shining dawn', and when (7) ............ (ABSOLUTE) pure, it can be moulded by hand. Which metal are we (8) ............ (DESCRIBE)? Gold! Yeaah!