Harry had carefully bought and wrapped presents for Mark to give them.哈里精心购置了礼物又仔细包好，让马克交给他们。Diana is taking the opportunity to wrap up the family presents.黛安娜利用这个机会将家人的礼物包起来。Jeff had shopped extravagantly for presents f...
This paper presents the development of acoustic immittance apparatus and application in diagnosis of ear disease.本文详细介绍了声导抗测试技术的发展及在耳科疾病诊断中的应用.This paper presents the contactless control of flasher with triode.提出了用三级管导通和...