题目内容：

   Mike and Dick work in the same office. They don’t like the cold weather. And one day they decided to take their holiday in Australia. Their plane arrived in Sydney at nine in the morning. They had a good rest in a hotel. The next morning they rented (租) a car in the city and began their travel. A few hours later, the sun was shining in the sky and there were no shade trees (遮阴树) beside the road. It was so hot that they could hardly go on driving. They had to stop to look around. Mike found a river about half a kilometer away from them. They were both very happy and drove the car quickly. Soon they got to the river. Before they jumped into the water, Dick saw a boy playing under a big tree. He asked,“Are there any sharks (鲨) in the river, boy?”“No, there aren’t,”answered the boy. So they began to swim in the river. After a while, Dick felt something hit against his leg. He told Mike about it. They were afraid and stopped swimming. Dick asked loudly,“Is it true that there aren’t any sharks in the river?”“Yes, sir,”said the boy,“There’re a lot of crocodiles (鳄鱼) in the water. All the sharks have swum away!”

根据短文内容，回答问题。

1.When did they arrive in Sydney?

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2.What was the weather like the next day?

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3.What did they do in the river?

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4.A shark hit Dick’s leg, didn’t it?

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5.Why weren’t there any sharks in the river?

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