Arecentstudy_________thatthespread

发布时间：2020-07-27 14:13:49

A recent study _________ that the spread of bird flu has something to do with the way poultry is kept and transported．A.has been provingB.has been provedC.will proveD.has proved

网友回答

D解析根据句意应使用动词prove的现在完成时的主动语态。
以上问题属网友观点，不代表本站立场，仅供参考！