![](https://static.youtibao.com/asksite/comm/h5/images/m_q_title.png)
He is sure that there was a flying saucer over there. If he hadn't seen it himself, he ____ it.
He is sure that there was a flying saucer over there. If he hadn't seen it himself, he ____ it.
A) never have believed B) never did believe
C) could never believe D) would never have believed
![](https://static.youtibao.com/asksite/comm/h5/images/solist_ts.png)