Explanation : (C) In the early 20th century, William Heard Kilpatrick expanded the 'Project Method' into a philosophy of education. His device is child-centered and based in progressive education.
Explanation : (D) The main important thing a teacher can do is provide a positive learning environment. This can be done by making classroom environment friendly
Explanation : (B) Hardware approach mechanises the process of teaching. It refers to the use of machines and other mechanical devices in the process of education. Hardware approach is based on the application of engineering principles.