Great changes ________ since we entered E-times. And the computer is widely used throughout the world.

The World Health Organization warned that Asian countries __________ attentive to bird flu since Asia ___________ got rid of the disease completely.

Public signs keep ________ from danger.

The manager said that they had an _____ plan if the plan they had submitted was not accepted.

Einstein’s most famous theory is ______ we call the Theory of Relativity.