“四呼”
参考答案：
按韵母开头的元音发音口形，又可以把韵母分为开口呼、齐齿呼、合口呼、撮口呼四类，简称“四呼”。
Tim will call me as soon as he ______ my package.
A. receive B. will receiveC. received D. receives
