Choose the words given to fill in the blanks correctly.

Once a month, the moon travels in a complete circle (1) the earth. As it movesin its circle, it (2) to change shape. This is because we, on Earth, (3) only that section of the moon that catches the sun’s light.

When the sun, the moon and the earth are in a straight line with the moon in the middle, it is impossible for us to see the moon. At this point, the moon is said to be new.We are unable to see it in this position because the side facing the (4) is inshadow. As the new moon begins to circle the earth, however, we begin to see that partof its surface that catches the sun’s (5) . After some days, when it reaches theposition where the earth is (6) the sun and the moon, we see the full moon.Later, it again (7) half moon, becoming smaller and smaller until it disappearsagain to become the new moon. This cycle takes 28 days or a lunar (8) .