Nitrogen is required for protein formation. What is responsible for the bulk of nitrogen fixation? A.
air

B.
animals

C.
bacteria

D.
lightning

The factor with the responsibility for nitrogen fixation is bacteria (option C).

Explanation:

The nitrogen that contributes to the formation of proteins comes from plants. Due to the inorganic nature of nitrogen, plants require bacteria to contribute to the assimilation of this element, a process called biological nitrogen fixation.

Nitrogen fixing bacteria in plants are called diazotroph and, in some cases, establish a symbiosis with the plant's roots, the rhizobia.

b. to discover aspects of the natural world.

hopefully i .

they had the law tat factories that produces smoke cannot be built near residential buildings.

building of proper sewage system was done to ensure that the waste is carried away from the humans so that they do not get diseases from it.

also they built water systems to provide water in those areas which are drought prone.