Standard for means it is written in words: four hundred ans fifty would be the answer.
A secondary source in when you don't get the information from the person who said let's say you asked what's for lunch today and they told someone to tell you fried chicken but they told you chicken sandwich the answer can change before it gets to you.
A run<span>-on is a </span>sentence<span> in which two or more independent clauses </span><span> are joined without an appropriate punctuation or conjunction = )
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Because he broke up with his girlfriend and that’s why he left