Use appropriate clauses at the pace of quoated Phrase. I have heard "of his failure". A ) I have heard when he has faced
B) I know he failed
C) I have hearded that he has failed
D) none of the above

Great amounts of electromagnetic energy from our sun and other bodies in space travel through space. which is a logical conclusion about these electromagnetic waves? their energy must be very their frequency must be very low these waves can travel without a medium they only travel through a vacuum of space