一个角补角比它的余角的2倍多30°，求这个角的度数．

从右栏选项中找出左栏各句的恰当应答。

                I                                                                                                   II

46. 1.Hello,Jenny speaking. ____                                             A.I like music that I can dance to.
47. 2.How often does Jeff go to the library? ____                   B. It's 876-9548.
    
48. 3.What's your telephone number?    ____                         C. They're pretty good.
    
49. 4.What do you think of the cartoons? ____                       D. Hi, Jenny. It's Steve.
    
50. 5.What kind of music do you like?  ____                            E. Hi, I'm Jack.
    

                                                                                                   F. Once a week.

写关于一句珍惜时间的名言名句。

①除去乙烷中少量的乙烯：通入H₂，加催化剂反应

②除去乙酸乙酯中少量的乙酸：用饱和碳酸钠溶液洗涤，分液

③除去NaBr溶液中的NaI：用氯水氧化NaI，再用CCl₄萃取分液

④除去工业酒精中少量的水：加足量无水CuSO₄，过滤

⑤KNO₃中含有少量NaCl杂质：可通过蒸发结晶的方法提纯

⑥除去碳酸氢钠溶液中混有的少量碳酸钠：可往溶液中通入足量的CO₂．