Which best explains why the cycle of Moon phases can be seen from Earth?

These phases are caused because half of the Moon is always lit by the Sun, but only part of the Moon's lit surface can be seen as the Moon orbits Earth, and Earth orbits the Sun. The diagram below shows the phases of the Moon as they relate to its orbit around Earth.

Explanation:

answer; (quadrupled)

the only other powers were germany russia and uk and they were too busy fighting each other wearing each other down   that the us was becoming strong and they were becoming weaker