单选题 5.   His parents are worried because they haven't heard of their son in more than two months.
【正确答案】 C
【答案解析】 应改为from。本题考查固定搭配。hear from为固定搭配,意为“收到……的来信”。
   他的父母很担心,因为他们已经两个多月没收到儿子的来信了。