What is the answer for this one?

Suggest why placing wheels under a heavy box reduces the neccessary force required to push it along at a constant speed.

Where can a dna be found in a prokaryotic cell

Ascience research group is testing a new type of plant food. one trial is conducted in a controlled experiment. the data from the trial show that the plant that received the new food grew faster than the control plant. the group announces that the new plant food makes plants grow faster. what is the main weakness in this scientific claim?