C) have + been + verb + -ing.
Answer:
Signals can travel as slow as about 1 mph or as fast as about 268 mph. Axon – a long, single nerve fiber that transmits messages, via chemical and electrical impulses, from the body of a neuron to dendrites of other neurons, or directly to body tissues such as muscles.
Explanation:
The Three Witches<span> first appear in Act 1.1 where they agree to meet later with</span>Macbeth<span>. In 1.3, they greet </span>Macbeth<span> with a prophecy that he shall be king, and his companion, Banquo, with a prophecy that he shall generate a line of kings.</span>
