题目

某市移动通讯公司开设了两种通讯业务：“全球通”使用者先缴50元月基础费，然后每通话1分钟，再付电话费0.2元；“神州行”不缴月基础费，每通话1分钟需付话费0.4元（这里均指市内电话），若一个月内通话 分钟，两种通话方式的费用分别为 元和 元. （1） 写出 ， 与 之间的函数关系式（即等式）. （2） 一个月内通话多少分钟，两种通话方式的费用相同？ （3） 若某人预计一个月内使用话费120元，则应选择哪一种通话方式较选用方框内单词填充短文。lotabovequicklytookwaterjumpedheardlisteningspendhotIt was sunny and again at this time of year. John went to the beach to his weekend. He was lying on the sand and to music. Suddenly he someone crying for help. He up hurriedly and looked towards the voice. He saw a little boy waving(挥动) his hands in thea little far away. He off his clothes and jumped into the water. He swam to the little boy, held him, kept his head the water and swam back to the beach. At last, the boy was safe. He thanked John a.