Several villages were_________from the outside world, for all roads to those villages were destroyed.

In our class, girl students _____ nearly 60% of the students, and most of them study very well.

---Can you think of another good idea?---This is the best approach I can imagine ______ the work ahead of schedule.

 The leader ordered that the boys ______ in the accident should be given first aid at once.

Scientists _______ a lot of experiments on animals, hoping to find and effective way to cure the patients who had AIDS.