Answer:
Four abiotic forms of nitrogen cycle and its chemical formula
Ammonium – 
Ammonia – 
Nitrite –
Nitrate – 
Explanation:
Ammonium: In the nitrogen cycle ammonium is starting point that is present in soil and are converted to various forms by different process.
Ammonia: In the process of nitrogen fixation, the bacteria having nitrogenase enzymes reacts with the nitrogen as well as hydrogen and produces the ammonia, which is further converted to organic compounds.
Nitrite: The nitrosomonas bacteria present helps in conversion of nitrogen gas into nitrite.
Nitrate: Again the Nitrite is converted into Nitrate by the nitrobacter. During the process of assimilation ammonium and nitrate are absorbed by the plants.
Comparative anatomy is the study of the similarities and differences in the structures of different species. ... Homologous structures are structures that are similar in related organisms because they were inherited from a common ancestor. These structures may or may not have the same function in the descendants.
Have a control. You have to have something to compare your experimental results or else your results could be random chance.
(B) All cars traveled at different speeds. Sorry if im wrong
I believe it’s A I think, I think I’m right