Three of the most important times to check traffic behind you are before:

Three of the most important times to check traffic behind you are before:Backing, changing lanes, or slowing down quickly
It is very important to have this in mind, because errors made when changing lanes are some of the most common causes of automobile accidents. Every driver must use proper lane changing techniques every time you switch from one lane to another.

Bob: coke is baby pandas.jim: what? how do you figure that coke is baby pandas? bob: because this book says so.jim: how do we know the book is correct? bob: because it says that coke is baby pandas.jim: how does that prove the book's accuracy? bob: because it's statement involving coke and baby pandas is correct, therefore it is accurate.jim: how do we know that it's correct? bob: because we have concluded that the book is accurate, and therefore the statement is correct.therefore, coke is baby pandas.