Questions

Cretinism is a disease caused by hypothyroidism(less thyroxine formation).The symptoms of the disease are retardation  of mental, physical and sexual developments. Potbellt, protruding tongue, dry skin etc are also indicative of this disease.

Ionic bonding is the complete transfer of valence electron(s) between atoms. It is a type of chemical bond that generates two oppositely charged ions. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion.

Hence, when Ionic bonds are formed metallic atoms tend to lose electrons and become positive ions

The process which wherein an Ecosystem may renew itself is known as Ecological Succession.

The time scale may be decades or a million of years after a mass extinction. 

It may be achieve over a period of time.

In 1933, Congress repealed prohibition with the 21st amendment. At it’s heart, the scopes trial was a clash between religion and science. Nativists were opposed to immigration because they feared that immigration would be a damage to America’s traditions and that it would result in a loss of jobs.

The Prohibition Era in United States history lasted from 1919 to 1933. It was defined by a complete prohibition of the manufacturing, sale, and transportation of alcoholic beverages in the United States.

A metaphor is a figure of speech that is used to make a comparison between two things that aren't alike but do have something in common.

In all the given options we have Metaphors.