There ___has been_______ great changes in our country since 1979.(be)这里填has been对吗?应该用完成时吧?

There ___has been_______ great changes in our country since 1979.(be)这里填has been对吗?应该用完成时吧?
There ___has been_______ great changes in our country since 1979.(be)
这里填has been对吗?应该用完成时吧?

There ___has been_______ great changes in our country since 1979.(be)这里填has been对吗?应该用完成时吧?
用have been吧
changes是复数

没错 有个since一般要用完成时的

对的

应用have been,因为后面的名词是复数形式.