Question

what needs to be emphasized in this step when reading? \turn the two - bottle assembly over, and place the assembly on a table with the filled bottle on top. watch the water slowly drip down into the lower bottle.... now, rapidly rotate the bottles in a horizontal circle a few times. observe the formation of a funnel - shaped vortex...\ a. rapidly rotate the bottles in a horizontal circle c. both a and b b. watch the water d. neither a nor b

Explanation:

When reading the given text, both actions - "Watch the water slowly drip down..." and "rapidly rotate the bottles..." are important steps in the described process. The first part is about observing the water dripping (related to the initial state and a basic observation), and the second part is about the action of rotating the bottles to observe the vortex formation. Both are key elements in the described procedure.

Answer:

c. both A and B