单选题
The rules laid the foundation for a major (restructuring) in gas pipeline operations by requiring pipelines to charge (separately) for each of their services and by making them available (on equal basis) to anyone (desiring) to use them.
【正确答案】
D
【答案解析】[解析] 选项D所对应画线部分与之后内容作后置定语修饰anyone, be desired to do sth. 为固定搭配，指“渴望做某事，想要做某事”。因此把desiring改为desired。