It was reported that many helicopters were sent there______the missing passengers.[ ]

They walked together as far as the second crossing ____ they parted

have started getting up at 5:30 a.m. to study;I don’t know if I can this.

Many audiences listened to his speech very attentively from the very beginning to the end, my parents ___________.

Stephen Hawking believes that the earth is unlikely to be the onlyplanet life hasdevelop gradually.