Barter system- A method of exchange when no money is involved.
B and C can't be the answers because they are not exchanging anything.
D can't be the answer either because there is money involved.
So your answer is A) You trade an apple for a banana at school. because you are exchanging something with someone for something else thats not money.
Hope this Helps!!
Many effects of aging can be diminished by regular exercise.
Staying active will keep the body healthy and young, as what researchers from the University of Birmingham and King’s College London has found.
The researchers studied a young group and middle age adults who didn’t usually exercise, and they were compared to the group of elder people who frequently exercised in their whole lives. The results showed that aging process have been defied by those who exercised regularly.
The Space Race was a period when the United States and Soviet Union
competed for technological advancements and scientific accomplishments.
This competition was a result of the Cold War that started after World
War II.
Exploring space during this era (late 1950's through the
beginning of the 1970's) was an unprecedented adventure for its time.
The world was shocked when the Soviet Union were able to launch Sputnik (
a satellite) into space. After this momentous accomplishment, the US
followed sending their own satellite into space several months later.
Both
of these countries took a significant risk, as their satellites,
spaceships, and other equipment could completely blow up. This would
result in the deaths of citizens. Along with this, they had to risk the
financial risk that this race caused. Each country poured in hundreds of
millions of dollars into their space programs over the course of 2
decades. If countries failed to achieve any breakthroughs, then this
money would have been wasted.
Despite the risks, this space race
had several positive effects on the world. This includes the
implementation of satellites that allow us to use GPS, the invention of
memory foam mattresses, and increased funding for public education.
Answer:
The answer is - The Root Node
Explanation:
The Phylogenetic tree shows the relationship between different organisms and their path of evolution through time. It is a graphical representation that links organisms from a common ancestor down to their different descendants. The most recent common ancestor of all the taxa or organisms on a phylogenetic tree is represented by a root node as it is the very first parent or node.
