改错 1.they have gone to beijing twice this year. 2.i hear that one of the students have come back

Question

如题所述

Answer 1

1 have gone 改成have been，因为去过2次，已经回来了，用have been to
2 have改成has，因为one of ，是一位，单数概念，因此谓语用单数

Answer 2

1，gone 改为been
2 , have 改为has