He is quite sure that it’s____impossible for him to finish the task within two days.

My mother has not yet recovered from the illness, but she is __________ getting better.

He never gave up his dream and ______ achieved his goal.

What a terrible experience ! ________, you’re safe now —— that’s the main thing.

These natural parks are very important for preserving many animals, which would ______ run the risk of becoming extinct(灭绝的)．