What is the best possible way to verify claims a manufacturer makes about a supplement's safety and effectiveness? the manufacturer's website the product's commercial advertisement the us food and drug administration website a consumer's blog review

The answer is the US Food and Drug Administration website.

The FDA is responsible for monitoring the effectiveness of all products that the public consumes, from foods, vaccines, drugs, and animal feeds. In its website, it has a review for every product released to the public that determines its quality and approval status.

U.S food and Drug administration

Explanation:

It keeps moving in a straight line, in the direction that we call "down".  

But its speed keeps getting faster and faster.  At any instant, its speed is 9.8 m/s faster than it was 1 second earlier.