1. I think you should compare diagrams of moon phases from the textbook to diagrams of moon phases online. Because if you pick D it will take to long and C will help you out whith 3 different things to look at.
2. The moon changes in appearances from the perspective of people on earth because it's revolving around the planet and the earth is revolving around the sun, so A. Hoped this helped.
For question 1, I would go with option B. This is how science works. You start off with a hypothesis and then you test to see if what you observe matches the hypothesis. For option A, you risk not getting complete data. If the night you pick to start happens to be a full moon, you're done before you start. Option C is only comparing one set of stated facts against another set of stated facts. You have to trust these at face value. Both could be wrong. Option D says "as often as possible" which is too vague. If it was every night, then you would have your evidence six times over. If you can only test every 28th day, then you're going to see the same phase of the moon each time.
Question 2: The answer is B. The moon revolves around the Earth. As the Moon orbits the Earth, it is in a different part of the sky with relation to the Sun. When the Moon is fully behind the Earth, the Sun shines straight on and we see a full moon. When the moon is between the Earth and the Sun the light from the Sun falls on the side farthest away from the Earth and so we don't see it. Here is a diagram to illustrate http://www.moonconnection.com/images/moon_phases_diagram.jpg
The piece of paper has less mass and will glide down the window, whereas the textbook will go straight to the ground. Since the textbook has more mass and less ways of it being able to 'glide' the textbook will hit the ground first.
