Learning in the four walls of a classroom implies

Read the passage below and answer each questions that follow:

Weathering, which is the gradual breaking down or disintegration of rocks into smaller particles or fragments by either physical or chemical process, can be affected by many factors. Generally speaking, the climatic condition of a particular area has a great effect on the weathering. Physical or mechanical weathering needs temperature and water. 

Chemical weathering, on the other hand, thrives where the climate is hot. We were all taught all these in the four walls of the classroom. I made a visit to my village to see these scientific discoveries. I noticed big trees with their roots penetrating into rocks and breaking them. I initially wondered and puzzled seeing trees growing from the rock. 

A similar thing happened to the soil sampling surrounding where there were rocks. I could see the rock particles mixing up with the rest of the soil.