The Challenger expedition (1872-1876 ) was a unique and historic voyage. Why?
A) It is the longest continuous scientific oceanographic expedition on record.
B) Its scientists developed the first reliable navigational charts to indicate current and wind patterns.
C) It was the first expedition to use an echo sounder to study the seafloor.
D) It proved the hypothesis that life could not exist in the deep sea.
Question 2
What contributes to the high biological activity and surface nutrients in southern polar waters?
A) Deep-water upwelling
B) Weak stratification
C) There is a lack of continental margins
D) All are contributing factors