I / sure / they / be / very happy / be / together / 25 years

 I / sure / they / be / very happy / be / together / 25 years

GRAMMAR (Ngữ pháp)

Đề bài:

a.      I am sure which they have been very happy to be together for 25 years.

b.       So I am sure of they have been very happy to be together for 25 years.

c.     I am sure that they have been very happy to be together for 25 years.

d.      That I am sure they have been very happy to be together for 25 years.
c.     I am sure that they have been very happy to be together for 25 years.