Answer:
1. Since the 1700's, people have used balloons filled with gas lighter than air to float above the ground.
2. Inventors have been trying since as early as the 1800s to create a heavier-than-air machine that would fly.
3. Originally the machines were not meant to carry people.
4. Wilbur and Orville Wright were the first to fly a powered airplane in sustained height.
5. At Kitty Hawk, North Carolina, the flight lasted 12 seconds, and went 120 feet.
6. They succeeded, they had studies aerodynamics, the principles of the movement of air around objects.
7. From this beginning, the airplane industry was started.
8. Louis Bleriot, a Frenchman, was the first pilot to fly across the English Channel in 1909.
hope this helps! :)
PCM: Pulse code modulation. It is a method used to digitally represent sampled analog signals. It is the standard form of digital audio in computers, digital telephony and compact discs. The amplitude of this signal is sampled regularly at uniform intervals.
PAM: Pulse amplitude modulation. It is a form of signal modulation where the message information is encoded in the amplitude of a series of signal pulses.
Answer:
C. The particles break connections among brain cells.
