题目

若椭圆两个焦点为F1（-4，0），F2（4，0），椭圆的弦AB过点F1，且△ABF2的周长为20，那么该椭圆的方程为__________. 答案：解析：c=4,4a=20,a=5,∴b=3,椭圆方程为=1.答案：=1选词填空。 forget, bring，mend，beside，luck，pick，same，differently, I ，every , stop，each      Mr. Brown had an umbrella shop in a small town. People sometimes 1 ________him broken umbrellas, and then he took them to a big shop in London. They were 2_______ there.     One day Mr. Brown went to London by train. He 3 ________ to take an umbrella with him that day. Sitting in front of him was a man with an umbrella standing 4 _______ the seat. When the train arrived in London, Mr. Brown 5 ________ up the umbrella as he often did during his journey by train. Just as he was getting off, he was 6 ________ by the man. He said angrily, “That’s 7________   !” Mr. Brown’s face turned red and he gave it back to the man at once.     When Mr. Brown got to the big shop, the shopkeeper had got his six umbrellas ready. After a good look at 8 ________  of them, he said, “You’ve mended them very well.”     In the afternoon he got into the train again. The 9 ________ man was in the same seat. He looked at Mr. Brown and his six umbrellas, “You’ve had a 10 ________ day,” he said.