Question

which contribution to the body of scientific knowledge is most recent?
the development of the lever
the discovery of the structure of dna
the discovery of electricity
the theory of evolution

Explanation:

The development of the lever dates back to ancient times. Electricity was discovered in the 1700s. The theory of evolution was proposed in the 1800s. The structure of DNA was discovered in 1953, making it the most recent contribution among the options.

Answer:

the discovery of the structure of DNA