Julie finds a snail on the sidewalk and wants to know whether or not the snail moves throughout the day. She places a single mar
k on the sidewalk next to the snail. What will Julie use the mark for initially?
determining how fast the snail moves
acting as a standard unit of measure
determining the displacement of the snail
acting as a reference point for detecting motion
Water vapor is the most abundant and dominant GHG in the atmosphere. Its concentration depends on temperature and other meteorological conditions, and not directly upon human activities.
