Observation the action or process of observing something or someone carefully or in order to gain information:
Domain of a function is the type of parameters it takes as input. The domain of a sine function is angle in either degrees or radians. The function that represents the population growth of the bacteria that is tripling every minute is given by the mathematical expression,
,
where, t is time in minutes, 
is the initial population size, and 
is the population at time, t.
The domain of this function will be time, t.
It's an sight observation you're using your eyes to see it it's one of your 5th sences
The barrier is cultural differences.
John, growing up in America learned that eye contact is a way of respect and to show you are paying attention.
Where Cho, growing up in Asia, many Asian counties don't have this "custom" to call it that.
B . to supply energy for splitting the water molecules
