Use of English · Part 3
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…
Desbloqueja tots els exàmens, simulacions il·limitades, les 80 fases del joc i molt més.