Traditionally, the woman has held a low position in a marriage partnerships. While her husband went his way she had to wash, stitch and sew. Today the move is to liberate the woman, which may in the end strengthen the marriage union. Perhaps the greatest obstacle to friendship in marriage is the amount a couple usually see of each other. Friendship in its usual sense is not tested by the strain of daily, yearlong cohabitation. Couples need to take up separate interests (and friendship) as well as mutually shared ones, if they are not to get used to the more attractive elements of each other’s personalities. Married couples are likely to exert themselves for guests—being amusing, discussing with passion and point—and then to fall into dull exhausted silence when the guests have gone. Once a man confessed, "The great question I have not been able to answer is ’What does a woman want’" Many husbands wonder the same thing today.

IP电话作为一个新兴的事物，受到了大家的欢迎，省钱是其最大的优点，但是IP电话也有不足，以下不是IP电话的缺点的是（）。

A.网络有时延

B.网络有时拥塞

C.话音质量不稳定

D.不能打国际电话