Biology Module 2 test
I need help with this

How many trophic levels are there in the following food chain? phytoplankton - shrimp - perch - pike - osprey

Arepair man charged $93.06 the price included 2 hours of labor and 40 service charge how much does the repairmen charge per hour for labor?

Johnny rode his bike to a friend's house 4 blocks down the street in his neighborhood. he immediately rode back home once he realized his friend was not able to play. what was his displacement for the total bike ride? how did you determine this? what could we use as a reference point to determine he was in motion during his bike ride? why can you use it as a reference point