Carbon 14 has a half life of 5,730 years. Scientists measure how much carbon 14 the rock has. For objects older than 50,000 years, scientists will test the age of the things surrounding it.
only about 3% because all of the other water would have to be filtered incorrect to be safe to drink so the student was incorrect in saying that there was water directly for humans to drink
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.
Polypeptide:
A chain of amino acids linked together by peptide bonds and having a molecular weight of up to about 10,000.
Dipeptide:
A peptide that yields two amino acids on hydrolysis.
