2008 山东 第 63 题 单选题 区分题 2008_山东卷 (英语) 63. The carriers’ $participation in the system is determined by _______.$ A. the US federal governmentB. mobile phone usersC. the carriers themselvesD. the law of the United States 参考答案C ☆ 收藏不会,直接看解析查看原卷 →