A series of pre-recorded tapes ___ (have,has)been prepared for the language laboratory 选什么 为什

A series of pre-recorded tapes ___ (have,has)been prepared for the language laboratory 选什么 为什 a series of pre-screening of a position. pre calculus 11的一道题 What is the value of S9 for the series 8-24+72-216+…?a 39366 b -13122 c 52491 d 39368 是a series of factors还是a series of reasons a series of a serious of 区别 the last of a series of competitions a series of ,后面加什么词 a series of books翻译成中文 用a series of造句,急用! set down a series of的意思 a series a series a series a series of和a trail of的区别 a series of后是不是可以跟可数复数名词,也可以跟不可数名词?a series of development a series of books 英语this pulishing house is designing 空school textbooks填of a series of 还是a new series of ,为什么 英语翻译A light on the Christmas tree—an eight-foot structure at the center of the racetrack with a series of colored lights on it—lit up,indicating that I’d just passed the pre-stage beam,an invisible laser that crosses the track.It lets y