Question

how long is the grand canyon? select the best estimate. 450 meters 450 millimeters 450 kilometers 450 centimeters

Explanation:

Step1: Recall size of Grand - Canyon

The Grand Canyon is a very large natural formation. We know that meters, millimeters, and centimeters are too small units for its length.

Step2: Analyze the units

Kilometers are a more appropriate unit for measuring the length of a large - scale natural feature like the Grand Canyon.

Answer:

450 kilometers