The answer is D.The cost of communication has decreased overtime,causing trade to increase.
In the past,communication technology was not as advanced as nowadays. Paasing a message even in the same region would be difficult not to mention overseas.
Imagine back when people can only deliver message by letters, the shipping or transporting fee would be much higher than what we're doing now, sending a simple text and delivered to the target easily. Not only would it be more costly economically,but also on time arrangement.
Time cost is very important for trading,as the situation,such as the demand of the market would shift very quickly from time to time. In the past,by the time a message was exchanged,the situation might have been different already. Or,in some cases,it might not be able to catch up with policies that government newly introduced on market.
Thus people would consider less about trading overseas as spreading the market would not be easy.
However nowadays with technology,communicating has become a very easy thing as long as you have the internet. It allows people to spread their brands globally as they can be able to monitor them more easily through communication. It is also easier for traders to exchange and collaberate. Much business chances are provided hense increasing the trading over the world.
Hope it helps!
Scientific Thinkers didn't accept it immediately because its has no proof or lack of information that needed to be prove by all others scienctific thinkers
Answer:
It is related to how the sun's rays strike the surface of the Earth.
At the equator, the rays strike the Earth almost perpendicular to its surface, warming up a small area. At high latitudes, the curve of the Earth causes the rays to strike a larger surface area, so the same amount of heat is distributed over a larger area. That means it does not warm up as much as at the equator.
This difference in temperature between the equator and the poles causes our atmosphere and ocean to circulate.
But in the ocean there is another effect. The sun at the equator also warms the surface ocean and causes water to evaporate. This makes the ocean more salty. In other areas, where there is a lot of rain, the ocean is less salty.
It is the combination of differences in temperature and salinity that causes the deep ocean beneath the reach of the wind to circulate.
Change of habitat from a species
