Which theory belongs in place of the question mark in tran’s timeline?

Assuming that the timeline that you're referring to is in the year of 1803, the theory is probably belong to Dalton
In 1803, John Dalton proposed a theory that would change the field of chemistry for the rest of the time, which is the discovery of atom

hope this helps

Firstly, the water in the dams hold gravitational potential energy as they are above ground level. the gravitational potential energy is then transferred to kinetic energy as it falls, spinning the turbinethe turbine then spins the generator, which is a large magnet surrounded by metal coils. by doing this, the generator generates electricity. in this action, the energy transfer taken place is kinetic to electric energy