The first Image to the left of first row=List of materials needed in a project
The second Image in first row=An implementation of a strategy
The first image from the left on the second row=A discussion on hierarchy on human needs
The second image on second row=An analysis of various ecosystem
Explanation:
The first image shows a list, while the image with the human hand shows a strategy being explained, the third which is the pyramid shows hierarchy, more like food chain and the last image shows the ecosystem, which is various part of the world.
