题目

一个三角形的三个内角度数比是3：4：5，则此三角形是（ ）A.锐角三角形B.直角三角形C.钝角三角形 答案：【答案】A【解析】解：180°÷（3+4+5）=15°，则15°×3=45°；15°×4=60°；15°×5=75°；三个角都是锐角，所以这个三角形是锐角三角形．故选：A．阅读理解。     Joan worked in a hospital as a nurse. One evening there was a big dance at the hospital. Most of the doctors and nurses would be there, but of course somebody had to be left to look after the sick children, and Joan was not of the lucky ones. She liked dancing very much, so when she had to start work that evening while her friends were getting ready to go to the dance, she felt very sorry for herself.      She went to each sick child one after another and said good-night, until she came to one little boy, Dick. He was eleven years old, but he was already able to talk like an adult. Poor Dick had a very serious illness, and now he was hardly able to move any part of his body except his hands. Joan knew he would never get any better, but he was always happy and always thinking about other people instead of himself.      Dick knew that Joan loved dancing. So when she came to say good-night to him, he greeted her with the words,"I'm very sorry that you have to miss the dance because of us. But we are going to have a party for you. If you look in my drawer, you find a piece of cake. I saved it from my dinner today, so it is quite fresh. And there is also a dollar there. You can buy something to drink with that. And I'll get up and dance with you myself if I was able to," he added.      Suddenly the hospital dance seemed very far away and not at all important to Joan. 1. Joan felt unlucky that evening mainly because ________. A. there was a dance ball at the hospital B. of her unpleasant job C. she would lose the chance to go to the big dance at the hospital D. she hated to look after the children 2. Poor Dick ________. A. was an adult. B. loved dancing C. was badly ill in the hospital D. could move freely except his hands 3. Dick was lovely because ________. A. he was always talking like a child B. he was always thinking about others more than himself C. he saved a piece of cake for himself D. he could foresee (预知) that he would never get better 4. Which of the following is NOT true? A. Dick got up to greet Joan when she came. B. Dick heard about the dance. C. Dick knew why Joan was unhappy. D. Dick showed sympathy (同情) for Joan. 5. At that party for Joan, Dick probably ________. A. got up and dance with her B. gave Joan some cake he had saved C. brought her something to drink D. lost the dollar which he was going to give Joan