[填空题]The origin of Earth’s moon, the largest moon in the (36) system, is still something of a mystery. There are some theories about its origin however. Now, keep in mind that a theory of the moon’s origin has to be (37) with two important facts. The first fact is that the Earth (38) a lot of iron, most of it has an iron core. But the moon contains (39) no iron. The second fact is that other than the difference in iron content, the moon and Earth are (40) of the same minerals, a (41) not shared with any other planet or moon in our solar system. One of the earliest theories of the moon’s origin, I called it the Capture Theory, proposes that the moon was somehow captured by Earth’s gravitational force. This theory is improbable, (42) , because it assumes that the moon and Earth formed in different parts of the solar system. If this was true you would (43) the moon’s composition to be much different from Ear