________wasthattheplanehadreached

发布时间：2020-07-27 02:50:08

________ was that the plane had reached the sound barrier．A.That had happenedB.That happenedC.Which had happenedD.What happened

网友回答

D解析主语从句。
以上问题属网友观点，不代表本站立场，仅供参考！