16.Believe it or not,he was seen_____ upstairs just now.
问题描述：
16.Believe it or not,he was seen_____ upstairs just now.
A.to go B.to going C.having gone D.go
17 Do you consider_____any good attempting many scientific experiments?
A.there B.it C.this D.that
18 There was a terrible noise_______the sudden burst of light.
A.followed B.following C.to be followed D.being followed
19 Is_____necessary to change trains at Beijing?
A.this B.that C.it D.he
答
16.see 感官动词 主动用法有两种 see sb.do sth./see sb.doing sth.由于是 被动语态 如果主动语态中是不带to的不定式结构 如 see sb.do sth.改成被动语态要加上 to 所以A正确不选择C的原因是 just now已经强调了动作...