Final answer:
The statement '30 cm³ of carbon dioxide in a canister' is not an example of length, as it represents a volume. Length refers to a measure from end to end in units of distance.
Step-by-step explanation:
The question is asking for an example of length, which is a measure of the extent of something from end to end. The correct answer is expressed in units of distance, such as meters, centimeters, or inches, and it does not involve volume or mass.
Therefore, 30 cm³ of carbon dioxide in a canister is not an example of length as it represents a volume, specifically the amount of space occupied by the carbon dioxide. Instead, an example of length might be the measurement of the side of a book in centimeters or meters.