Forms of condensation: dew, frost, fog, and mist

Correct answer: A. Fog is a cloud-like form near the ground

The correct answer is A. Fog is essentially a cloud or cloud-like mass of very small water droplets, and sometimes ice particles, that forms at or close to the Earth’s surface and reduces visibility. Ordinary clouds form above the ground, while fog remains near the surface; the main distinction is therefore height or location, not a completely different substance. B is wrong because hail consists of solid ice pieces and is not fog. C is false because clouds form in the atmosphere, not inside the ground. D has no physical meaning: clouds and fog are connected with condensed water, not dry fire. Memory cue: same basic water droplets, different height—cloud above, fog near the ground.

Correct answer: C. Rain

Correct answer: C, rain. Precipitation type depends on the temperature conditions along the particle’s path from the cloud to the ground. Ice crystals formed in a cold upper layer may begin their descent as snow or ice. If they pass through a sufficiently warm lower layer, the ice melts and becomes liquid water. If the melted drops remain liquid until they reach the surface, the observed precipitation is rain. Option A is wrong because frost is ice deposited on a cold surface, not melted falling precipitation. Option B is wrong because fog is a cloud at or near the ground, not the usual result of falling ice crystals melting. Option D is wrong because mist is a near-surface suspension of tiny droplets. C is correct because the warm layer melts the crystals. Memory cue: “cold aloft plus warm air below can turn falling ice into rain.”

Correct answer: A. It removes vegetation and exposes soil to erosion

The governing process is land degradation caused by the removal of protective vegetation cover. In overgrazed land, animals consume grasses faster than plants can recover, and repeated trampling may compact the soil. Without roots and plant litter to hold and shield the surface, wind and rain remove fertile topsoil more easily. Lower soil fertility and reduced water infiltration then make vegetation recovery still harder, creating a feedback that can promote desertification. Overgrazing does not increase rainfall, water harvesting or soil organic matter as stated. Therefore option A correctly identifies the immediate mechanism and the best answer.