Answer: A) reabsorption of excess neurotransmitter molecules by a sending neuron Explanation: Reuptake refers to the process in the brain of neurons to retrieve chemicals that were not received by the next neuron. Neurons are cells in the brain that have miniscule spaces between them. They communicate with each other by sending chemicals across the space to the next neuron.

Answer: A) Hertz Explanation: CPU speed is the central factor in a computer's performance. And this CPU speed depends on the processor in the CPU chip. In a computer, clock speed refers to the number of pulses per second generated by an oscillator that sets the tempo for the processor. Clock speed is usually measured in Hertz (Hz).   But now-a-days, a pure processor's performance is measured in MIPS (Millions of Instructions Per Second). As here in the question, how a processor's speed is measured is asked and it is Hertz.    Hence, Processor's speed of a computer is measured in Hertz(Hz) [MHz, GHz].