As there is less and less coal and oil, scientists are exploring new ways of making use of ____ energy, such as sunlight, wind and water for power and fuel.

You must keep away from the man, who is ______. If you are ______, please call the number 110.

Medicine shouldn’t be kept where it is _____ to children.

There was a fire accident in the hotel last night. Fortunately everyone had a(n) _____ escape from the fire and no one was hurt.

The Beijing Olympic Games has been the biggest ________ Games in the world.