为鼓励居民用电，某市电力公司规定了如下电费计算方法：每月用电不超过100度，按每度电0.50元计费；每月用电超过100度，超出部分按每度电0.40元计费．
（1）若某用电户2002年1月交电费用68.00元，那么该用户1月份用电多少度？
（2）若某用电户2002年2月份平均每度电费0.48元，那么该用户2月份用电多少度？应交电费多少元？
解：（1）该用户1月份用电x度，依题意得：100×0.5+（x﹣100）×0.4=68，
∴x=145．
答：该用户1月份用电145度．
（2）设用户2月份用电y度，依题意得：100×0.5+（y﹣100）×0.40=0.48y，
∴y=125，
∴0.48y=60．
答：该用户2月份用电125度，应交电费60元．
| 阅读下面短文，从短文后面每题所给的四个选项中选择最佳的一项。 |
| There would be a school party on Friday evening.The girls were talking about what they were going to wear. "I'm going to wear a black dress, so everybody will notice(注意) me, " said Emily."How about you, Linda? " "I'm not sure. Maybe jeans(仔裤), an old shirt, and a hat.People will notice me more than you! "Linda said. "What are we going to do about the boys? " asked Jane."Do you remember the last school party, last year? They just stood there, and we girls had to dance by ourselves! " "I hear that some of the boys learned how to dance this summer. Maybe it'll be better this time, " said Mary. The party was held on Friday evening.Groups of students arrived. The music began. The girls stood in a line on one side, and the boys on another side.Mr Green, their teacher, tried to get them together, but failed. After a while, Tim said, "I don't want to stand here the whole time.The party is only for two hours. It'll be over soon."He started to dance. All the others watched him.Then David asked Emily if she wanted to dance. Then Jack and Linda. Then, all began to dance. Soon there were more dancers than watchers. |
| 1. On Friday evening there would be ______. |
[ ] |
| A.a school party B.a school meeting C.a sports meeting D.a birthday party |
| 2. The girls were talking about ______ . |
[ ] |
| A.what the boys were going to wear at the party B.what they were going to wear at the party C.how to teach the boys to dance D.how to dance |
| 3. What happened when the music began? |
[ ] |
| A.David asked Emily to dance. B.Groups of students arrived. C.The boys and girls began to dance. D.The girls stood on one side, and the boys on another side. |
| 4. Who was the first one to dance? |
[ ] |
| A.David. B.Jack. C.Tim. D.Jane. |