Factories began to replace running streams as a source of power for running machines with:

Steam and coal

Explanation:

Before the advent of the Industrial Revolution, running streams were an important source of power for machines. This was important for a great variety of industries. However, as industries developed further, more efficient ways of producing energy were discovered. Steam and coal became two important sources of energy, but also important pollutants in our environment.

the correct answer is 50.

the scientific revolution brought us a renewed understanding of humanity and our place in the universe, new scientific equipment, and new laws as a basis for future scientific discovery.