It is when either of the two times in the year, the summer solstice and the winter solstice, when the sun reaches its highest or lowest point in the sky at noon, marked by the longest and shortest days.
        
             
        
        
        
Answer: 30 year
Explanation:
The normal high temperature for a given day determined by the temperature of a place averaged over a period of time, often 30 years. This is also described as climate information. Climate information includes the statistical weather information that tells us about the normal weather, and also the range of weather extremes for a location. Most weather forecasters rely of past weather to predict the normal high temperature of a given day. 
The average high or low temperature is the normalized high or low temperature for at least a 30 year period. Therefore, an average high is a statistical average. Records need to be kept at least 30 years for an average high temperature, for the information to be statistically meaningful.
 
        
             
        
        
        
changes to the mutation is harmful
mutations are basic input of a organism
so playing with mutations is like inviting danger
it will give beneficial and neutral defects to the organism and may take life of it.
the biggest example is playing with virus which caused corona
 
        
             
        
        
        
Calcrete or Caliche is a type of sedimentary rock often found in arid and semiarid regions. It is composed of calcium carbonate with bits of gravel, clay and silt. It is found in Australia, Kalahari Desert, Sonoran and Mojave desert. Note that caliche does not form through dissolution and reprecipitation of rainwater. Rather, it forms when water from the ground rise above through capillary action, bringing up minerals from the ground into the surface.
 
        
             
        
        
        
History was a driving force behind such migration, since humans tended to move to new territory when they lacked food, shelter, or other resources--meaning that most of the conflicts throughout history have been driven by the same forces that drove migration out of Africa.