Before the final examination, many students have shown ______of tension. Some have trouble in sleeping while others have lost their appetite.

. It is clear that the whole world is passing through a social revolution in which a central _____ must be taken by scientists and technologists.

The tomato juice left some _____ on a customer’s skirt, which made the waitress nervous.

Those bad conditions have given ______ to a lot of crime in the area.

Some of the passengers told the reporters about their_____in the burning train.