The answer are C and D.
Whenever we <em>noticed a mistake</em> in an article published, but we are <em>not</em> completely <em>sure</em> what exactly is, we <em>should research</em> about the subject, in this case, by reading various <em>historical accounts</em>. After making sure we know what facts were left out, the <em>next step is to inform the edito</em>r of the publicaton about the case.
Answer:
A.
a formal and serious tone
Explanation:
Gravitational firce and speed,light i guess. LOL im not even sure is this is right
