Excited by the news, Marin lay in bed with her eyes ______ open while all her family were ______ asleep.

Travelling west, you set your clock ______; travelling east, you set it ahead.

It is one thing to enjoy listening to good music, but it is      another to play it well yourself.

.．As is often pointed out, knowledge is a two-edged weapon which can be used_____________for good or evil.

He began to take political science ________ only when he left school.