阅读理解。 About a hundred yards along the path, we came to a deep valley (山谷). On the far side of it, the path led into some very thick bushes, rather than push through up again and rejoin the path on the far side of the bushes. As I climbed down into the valley a bird flew off a rock on which I had put my hand. On looking at the spot from which the bird had risen I saw two eggs. They were a kind that I did not have in my collection, so I placed them carefully in my bag, wrapped in a little dry grass. As we went further down the valley the sides became steeper (陡峭) and not far from where I had entered it came to drop of about twelve to fourteen feet. The water that rushed down all these small valleys in the rainy season had worn (磨损,冲刷) the rock as smooth as glass. As it was too deep to climb down, I handed my gun to one of them and slid down it. My feet had hardly touched the sandy bottom when the two men jumped down, one on each side of me. They quickly gave me the gun and asked me if I had heard the tiger. In fact, I had heard nothing, possibly because of the noise I made sliding down the rock. The men said they had heard a tiger growling (咆哮) somewhere nearby, but they did not know which direction the noise had come from. 1. According to the passage we know that _______. A. the writer decided to cut down the thick bushes B. the writer decided to walk along the valley C. the writer wanted to stop climbing D. the writer tried to find two eggs 2. When the writer found the eggs, he _______. A. wrapped them in dry grass and left it on the rock B. wrapped them in dry grass and took them with him C. tried to find the bird D. made the bird fly off 3. The reason why the rock was hard to get down was that _______. A. it had been worn smooth B. there was no grass on it C. it was wet and slippery (滑) D. it was soft and sandy 4. At the end of the story, the writer knew that _______. A. a tiger had run away B. a tiger was close to them C. the men had seen a tiger D. a tiger had seen them