假设某一介质对于空气的临界角是30°，则光从空气射向此介质时的布儒斯特角是：（） A 发布时间：2017-06-10 08:51 │ 来源：www.tikuol.com 题型：单项选择题 问题： 假设某一介质对于空气的临界角是30°，则光从空气射向此介质时的布儒斯特角是：（）A.45°B.63.4°C.71.9°D.90°
题型：单项选择题 完形填空。 Mr. Green is a good teacher. He is 1 . There 2 fifty students in 3 class. Mr. Green and his students are 4 friends, too.Now some of the students 5 on the playground. Bill and Mike 6 . Tom and John are jumping. Maryand Lucy are 7 a kite. 8 girls are playing 9 . Mr. Green is playing 10 them. ( ) 1. A. empty ( ) 2. A. is ( ) 3. A. their ( ) 4. A. good ( ) 5. A. play ( ) 6. A. run ( ) 7. A. flying ( ) 8. A. Others ( ) 9. A. the football( ) 10. A. and B. full B. are B. her B. fine B. is playing B. running B. doing B. Another B. a football B. with C. kind C. are some C. its C. nice C. are playing C. are running C. playing C. The others C. games C. for D. happy D. aren’t any D. his D. all right D. are play D. not run D. sitting D. Other D. the game D. to 查看答案
题型：单项选择题 患者，女，76岁。面浮，下肢肿，腹部胀满有水，心悸，咳喘，咯痰清稀，脘痞，纳差，尿少，怕冷，面唇青紫，舌胖质黯，苔白滑，脉沉细。其中医证型是（）A.痰浊壅肺证B.痰热郁肺证C.痰蒙神窍证D.阳虚水泛证E.气虚血瘀证 查看答案
题型：单项选择题 某产品经两道工序产成，原材料分工序陆续投入，其投入进度与加工费用相同。原材料消耗定额为；第一工序40公斤，第二工序60公斤。在产品数量为：第一工序100件，第二工序300件。本月完工400件。月初和本月发生的费用为：原材料25000元，加工费用13500元。各工序在产品消耗定额按50%折算。 要求：(1)计算各工序在产品完工率和月末在产品约当产量(将计算过程和结果填入下表中)； (2)用约当产量比例分配法将原材料费用、加工费用在完工产品与在产品之间分配(列示计算过程)。 工序在产品完工率在产品约当产量(件) 1 2 合计 查看答案
，变压器视为理想的，
，则输出电压与输入电压的有效值之比为（）。
