Which of the following main industry/industries was/were developed...

The first industrial revolution, which began in the late 18th century, was primarily based on coal, iron, steam engines, and the mechanization of the textile industry (cotton spinning and weaving).

The second industrial revolution, which took place after about 1850, was characterized by rapid industrialization and the development of new industries such as steel, chemicals, electricity, and petroleum.

Therefore, the chemical and electrical industries were the main industries developed during the second industrial revolution.

Answer: Chemical and electrical