例句： He finds it hard to mix at parties.

例句： Air whether in the gaseous or liquid state is a fluid.

例句： I always rejoice in my comrades' achievements.

例句： This layer of rock contains a lot of flint.

例句： I wonder whether Mr Black has any roses in his garden.

例句： The ground is as hard as stone after the drought.

例句： A technician on probation was hit by a piece of falling masonry.

例句： They were able to position the yacht by means of radar.

例句： The factory is in frequent scarcity of raw materials.

例句： He rowed the boat across the lake.