Complete the conversations with the following words. bruise(擦伤); burn ; fall off; trip over(绊倒) A:Kim was telling me that Henry has had an accident. B:Yes. He __1__ his hand while he was trying to put out fire. A: What happened? B: A candle _2__ the shelf onto the carpet and set it on fire, And then he __3_ the lamp cable when he was ruhing to get some water. A:How scary! Is he OK? B:Yes,I think so. He ____4___ his knee when he fell, but it's nothing too serious, his hand is getting better and there's no real damage to the house.