Final answer:
The sign that indicates there is a low place in the road ahead is the 'Dip' sign.
Step-by-step explanation:
The sign that indicates there is a low place in the road ahead is the 'Dip' sign.
It is a yellow diamond-shaped sign with a curved line at the top and a series of bumps or waves underneath.
This sign warns drivers to expect a sudden change in road elevation, such as a dip or depression in the road surface.