(心脏复苏) to maintain (获得) a flow of oxygenated blood to the brain and heart.

　　Do this by pushing up and down on the centre of the chest, with your hands interlocked together, constantly until an ambulance arrives.

　　Push at a rate of 100 beats a minute.You can't harm them doing this and might just save a life.

24.People don't do first aid often because ________.

A.they are not doctors B.they think it is dangerous

C.it isn't their responsibility D.they are cold­ hearted

25.If the person's chest is not going up and down, it shows ________.

A.the person is dead B.first aid is not needed

C.you should start CPR D.an ambulance isn't necessary

26.Which of the following pictures is TRUE about CPR according to the passage?

27.What is the main idea of the passage?

A.First aid for drunk people. B.First aid for injured people.

C.First aid for unconscious people. D.First aid for choked people.

　　One afternoon Peter and Jim went out for a bicycle ride. When they passed a place they saw a large area of grass and bushes on fire and a strong wind was blowing the flames towards a village. The firemen had already arrived and were trying to put out the fire. The boys left their bicycles and ran towards the village to see if they could help to fight the fire. On the way they met two firemen.

　　"Quick, you boys," said one of the firemen. "Come and help us to pull a pump (泵) to the stream. We can't beat out the fire. The wind is too strong. The pump is our only hope."

　　The two boys ran further until they came to a heavy pump. They helped to pull it to a stream not far from the village.

　　Soon the pump was working well so the boys went to watch the fire. It had already reached the edge of the village. The boys saw that two houses were on fire, and the flames were attacking a third building. Suddenly there was a shout from one of the villagers.

"Keep away!" a voice shouted. "There's paint stored in that building." The boys