第21题: [单项选择]When the adjacency matrix method is used to store a graph, which of the statements is (are) true ( ) Ⅰ.the space required depends on the number of vertices Ⅱ.the apace required depends on the number of edges A. None B. Ⅰ only C. Ⅱ only D. Ⅰ and Ⅱ 参考答案:B