Questions

In the given options, "His stomach rumbled like an approaching train" is an example of Simile.

All the other options are examples of metaphors. 

Simile and Metaphor are both figure of speeches in English which are used for comparing things but the only difference is Simile uses LIKE or AS words in comparing and metaphor directly compares without using any words.

It is WATER.

Southern Democrats are members of the U.S. Democratic Party who reside in the South. All the above given were the part of agenda of southern democrats.

Using fear and violence for political gain is the part of the agenda of southern democrats most directly affected African American.

Donkeys and horses can be breed to make mules and hinnys.

A hinny is a domestic equine hybrid that is the offspring of a male horse, a stallion, and a female donkey, a jenny. It is the reciprocal cross to the more common mule, which is the product of a male donkey, a jack, and a female horse, a mare.

Karst is a type of landscape that is characterized by caverns, caves, sinkholes, and underground streams. These features were all caused by erosion of the underlying rock.

Limestone type of rock usually underlies a karst landscape.

The seven elements — helium, neon, argon, krypton, xenon, radon, and oganesson of Group 18 of the periodic table are Noble or Inert gases.

Radon is the heaviest and Helium is the lightest gases of the noble gases.

We know that 1 yard = 3 feet. 

A yardstick which is used for measurement has 3 feet long but it cannot walk.