I think Son Doong Cave is by far ____________ cave in Vietnam.

A. Is the Nile the longest river in world?

B. Is Nile the longest river in the world?

C. Is the Nile longest river in the world?

D. Is the Nile the longest river in the world?

A. Mary likes to visit the pagoda best.

B. Mary likes the pagoda to visit best.

C. Mary likes visit to the best pagoda.

D. Mary the likes to visit best pagoda.

A. This city has more than 2000 visitors every year.

B. This visitors has more than 2000 city every year.

C. This more than 2000 city has visitors every year.

D. This has city more than 2000 visitors every year.

A. high      

B. higher      

C. the highest      

D. more high

A. in      

B. on      

C. at      

D. for

A. I am have never a more beautiful waterfall before.

B. I have never been to a more beautiful waterfall before.

C. I have never be to a more beautiful waterfall before.

D. I have never been a more beautiful waterfall before.