What are the technical matters mentioned as the di...

Câu hỏi: What are the technical matters mentioned as the difficulty arising in the process of    obtaining fresh water from the iceberg?

A The prevention of rapid melting iceberg

B The filtering water and the funneling it to shore in a large amount

C The purifying the fresh water and carrying it to shore

D The prevention of rapid melting and the funneling to shore in great volume