若圆x2+y2-2x-4y=0的圆心到直线x-y+a=0的距离为22，则a的值为 发布时间：2017-04-21 13:07 │ 来源：www.tikuol.com 题型：选择题 问题： 若圆x2+y2-2x-4y=0的圆心到直线x-y+a=0的距离为22，则a的值为（ ）A．-2或2B．12或32C．2或0D．-2或0
题型：选择题 从II栏中选择I栏中句子的正确答语。 (I) ( )1. What do you think of this monkey? ( )2. What's the time, please? ( )3. Can you help me, Jim? ( )4. Are we all here today? ( )5. Is it time to go to school? ( )6. What's wrong with you? ( )7. Why not ask her? ( )8. Where does your sister work? ( )9. What does your father do? ( )10. Would you like to go with me? (II) A. It's a quarter past eleven.B. No problem. C. Yes, it is. D. I can't find my cat. E. Yes, we are. F. It's very cute and clever. G. Yes, I'd love to. H. All right. I. He is a driver. J. In a school. 查看答案
题型：选择题 --Do you have a _____? -- Yes, I _____ at a clothes shop.[ ]A. job, work B. work, job C. job, job D. work , work 查看答案
题型：选择题 计算立杆稳定性时，应选取其危险部位（或最不利部位），当脚手架以相同步距、纵距、横距和连墙件布置，且风荷载不大时，危险部位在（）。A、脚手架顶层立杆段B、脚手架半高处立杆段C、脚手架底层立杆段D、双管立杆变截面处的单立杆段E、双管立杆双管立杆段 查看答案