(a) (i) Classify specimens B and D according to their mode of formation. (ii) Name two other rocks for each mode of formation. (b) Given three differences b...

(a)(i) Classification by mode of formation

• Specimen B: a sedimentary rock (formed by the deposition, compaction and cementation of sediments in layers).
• Specimen D: an igneous rock (formed from cooled, solidified molten magma or lava).

(a)(ii) Two other rocks for each mode of formation

• Sedimentary (like B): limestone and shale.
• Igneous (like D): basalt and gabbro.

(b) Three differences between specimens B and D

(c) Three uses of specimen D (igneous rock) in agriculture

1. Used to control erosion on farmland.
2. Used for building farm structures and constructing farm roads.
3. Used for grinding and sharpening farm tools.

(d) Five disadvantages of an abundance of specimen D on farmland

1. It reduces the amount of arable land available for cropping.
2. It prevents root penetration and disturbs the growth of plants.
3. It makes tillage operations difficult and increases their cost and drudgery.
4. It causes farm implements to wear out quickly.
5. It predisposes man and animals to injury and provides a hideout for reptiles and rodents.