表示“某人说”后面跟直接引语时，有时用逗号，有时用冒号，它们的区别是什么？如：
She said, “If I were a boy I would join the army.” 她说，“我如是男孩，就参军。”
I just plucked a figure out of the air and said: “Would ￡1 000 seem reasonable to you?” 我随口说出一个数字问道：“你看1 000英镑合适吗？”