Not until quite recently _____ any idea of what a guided rocket is like.

Today, household chores have been made much easier by electrical （ ）.

These three teachers vary_____their manners of teaching.

The whole class couldn’t help _____ when they saw the haircut of their new classmate.

Peter was （ ） that there should be no misunderstanding on that point.

The Quality Control Staff is responsible _____ the quality of the products that come out of the factory.

Some cities have passed laws that allow coal and oil_____only if their sulfur content is low.

It was once a difficult time, but in the end everything _____ all right.

Dress warmly, （ ） you will catch cold.

He criticized everything and everybody, and even _____ his few friends.

One of my brother’s many faults is that he never（ ） anything very long.

There was nothing we could do _____ wait at that moment.