Natural: Grand Canyon.
Man made: London bridge
Clouds can cover up the sun, which is the natural source for heat everywhere. When the sun is not in sight, or thickly covered by clouds, this limits the suns radiation and heat waves therefore causing less light and heat.
Answer:
A and B are equally likely
Explanation:
The conditional probability is defined as follows:

where:
is the probability for X to occur, given that Y has occurred
is the probability that both X and Y occur at the same time
is the probability for Y to occur
Given two events A and B, we have:

and

In this problem, we are told that

Which means that:

Simplifying, we get:

which means that A and B are equally likely.
The answer is - Unlithified or poorly lithified sediments.
Rocks can exhibit ductility only if there's ulithified or poorly lithified sediments. With other words, this process can occur only if the rocks that are bending over under the pressure if there's soft layer/layers that will allow this to happen without causing big opposing pressure and make the rocks break.