Apowerboat is operating at night. which of these lights must be shown?

If the powerboat is operating at night, the light that must be shown is: A white masthead light
Since dark colors dominated the surrounding during the night time, a white masthead light will provide the exact contrast for the color in the surrounding, which makes it easily identified from far away.

Your answer is 120miles 

If you're looking for an even spread of clay, silt and sand, add a considerable amount of sand and some clay until the 3 even out". soil texture triangle. silty clay loam soil is approximately 20 percent or less sand, 25 to 40 percent clay, and 40 to 70 percent silt.