问题
Land animals are believed ______ from sea animals
A:to have developed
B:to have been developed
C:having developed
D:having been developed
B:to have been developed
C:having developed
D:having been developed
正确答案是：
同类题型
a lot of his friends at the party, ______devoted to ruraleducation like him
Is Jessica giving us a speech thisevening— No, it ________be her. She________ toJapan.
I’m not thedark any more.— Oh, you’re brave now. Great!
So difficult ______ it to work out the problem that I decided to ask Tom for advice.