It is vital that every piece of equipment ________ before the experiment.

How do you find James Cameron’s 3Dversion of Titanic ——Fantastic! It can’t be _______ andhas brought us a wonderful experience.

_______the people have become masters of their country _______ science can really serve the people

st summer vocation in the high school, _______Ispent a fortnight on the farm, is really unforgettable

His friends found to tell him everything that had happened.