Answer:
nitrogen cycle
Explanation:
Nitrogen enters the living world by way of bacteria and other single-celled prokaryotes, which convert atmospheric nitrogen— N 2 \text N_2 N2start text, N, end text, start subscript, 2, end subscript—into biologically usable forms in a process called nitrogen fixation.
Answer: Water can become a non-renewable resource if we contaminate all our rivers.
Explanation: For example, as groundwater is usually removed from an aquifer at a rate much greater than its very slow natural recharge, it is a considered non-renewable resource. Removal of water from the pore spaces in aquifers may cause permanent compaction (subsidence) that cannot be renewed.
Number 2 is B the sea level rising
Number 3 is C the lightbulb
Number 4 is D carbon dioxide
