英語三級每日口語(5.11)：Have you heard from Mary?

Have you heard from Mary?
    你收到瑪麗的來信嗎？
    今天的幾個句子是有關信件的：
    1.let me hear from you.
    你可要給我來信喲。
    2.We hear from Wuhan often.
    我們時常接到從武漢來的信。
    3.When shall I hear from you?
    什么時候聽你們回音？