So many people there!What happened?—A group of young people fought there.The police arrived,after the situation ecome calmer.

Jack didn’t pass the examination lastweek.—_______ He had been working so hard athis lessons.

The zoo worker told the visitors that in the case of a highly ________ animal,performance training is easy and not so painstaking. [ ]

The person sitting opposite _____ Mr．Smith is our new manager

geles Times reported that researchers may have found a way to ______ human life by changing certain genes, so that humans might expect to live twice as long.