阅读理解
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 was 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，回答下列问题。
1. When did they arrive in Sydney?
_____________________________________________
2. What was the weather like the next day?
_____________________________________________
3. What did they do in the river?
_____________________________________________
4. A shark hit Dick's leg, didn't it?
_____________________________________________
5. Why weren't there any sharks in the river?
_____________________________________________
和
；
。
，则物质A的结构式为： ________________ ；
中，D物质可发生反应生成一种生活中常用高分子，其化学方程式为： _____________；将物质E与过量的H2发生加成反应，其生成物的化学式为 _________ 。
和
都是无色液体，下列物质中可以用来鉴别这两种物质的是 （填序号）：①银氨溶液、②淀粉溶液、③溴水、④酸性KMnO4溶液；
与物质
发生“Diels-Alder反应”的生成物为： ___。