The computer was used in teaching. As a result, not only _______, but students became more interested in the lessons.

The factory was built in a secret place, around ________ high mountains.

The experiment shows that proper amounts of exercise, if ______ regularly, can improve our health.

The old couple have been married for 40 years and never once ______ with each
Other.

____ about the man wearing sunglasses during night that he was determined to follow him．

____ St Paul’s Cathedral built after the terrible fire of London in 1666. It looked splendid when first _____!

_____on the grass _____singing and laughing.

Only by practicing a lot _____ our English well enough to communicate with foreigners.

____ in a sandstorm was a terrible experience. Nowhere _____ but to stay at home.

Nuclear energy may be dangerous if