The air-conditioner thrummed.空调嗡嗡作响。The room is cooled with air conditioner.这房间用空调降温.It was so hot that we had to have the air conditioner on all day long.天太热,我们不得不整天开着空调....
In education, the pendulum has swung back to traditional teaching methods.教育界又恢复了传统教学法。The ball which hung the roof is compound pendulum.悬挂在墙上的钟来回摆动.The familiar pendulum swing was to happen once more, and then stop.常见的钟...