_______ only in the Andes, the plant is used by local people to treat skin diseases.  

A. The / a

B. Ø / a

C. A/ the

D. The/ the  

A. But

B. Therefore 

C. However 

D. Thereby  

A. Hardly had my eldest started working as a freelance journalist when she graduated from university.  

B. No sooner had my eldest sister graduated from university than she started working as a freelance journalist.  

C. No sooner had my eldest sister started working as a freelance journalist than she graduated from university.  

D. After my eldest sister graduated from university, she had started working as a freelance journalist.  

A. On their return from the trip

B. They had returned from the trip  

C. To have returned from the trip

D. After they have returned from the trip  

A. Mark has been investing in improving education in less developed areas of New York.  

B. The legal dispute that Mark faced started in 2006 and continued well into 2011.  

C. Some of the creators of Harvard Connection used to be Mark's fellow students.  

D. Mark has deliberately taken the ideas of the creators of Harvard Connection.  

A. will make

B. on the domestic

C. put forward

D. promote sales  

A. taken 

B. validated 

C. revoked 

D. ratified