9. which of the following accurately describes circuits?
a. in a series circuit, the amount of current passing through each part of the circuit may vary.
b. in a series circuit, the current can flow through only one path from start to finish.
c. in a parallel circuit, the same amount of current flows through each part of the circuit.
d. in a parallel circuit, there's only one path for the current to travel.

Iknow the answer is a but i don't know why

Mrs. smith ordered a root beer float (vanilla ice cream + root beer). mrs. smith noticed that the three states of matter (solid, liquid, and gas) all existed simultaneously in her root beer float. a. identify each phase of matter in the root beer float. b. describe the particles of all three phases of matter in the root beer float. (how are the particles arranged and moving? ) c. identify one phase change you would see in a root beer float and described what causes this change.

Adrop of acetone (nail polish remover) has a mass of 35 mg and a density of 0.788 g/cm3. what is its volume in cubic centimeters?