Which of these provides most of the oxygen in Earth's atmosphere?
A B C D
coral reefs rainforest plants ocean phytoplankton continental grasslands
Question: Which of these provides most of the oxygen in Earth's atmosphere?
(A) coral reefs
(B) rainforest plants
(C) ocean phytoplankton
(D) continental grasslands

Answer: (C) ocean phytoplankton
Answer: (B) rainforest plants
Question: Which of these provides most of the oxygen in Earth's atmosphere?
(A) coral reefs
(B) rainforest plants
(C) ocean phytoplankton
(D) continental grasslands
Answer: (C) ocean phytoplankton