单选题 The sun shines because it is made of glowing gases. It gives off its own light. The moon shines too, but it doesn't give off any light of its own. We can see the moon only because it reflects light from the sun.
The moon travels around the earth about every twenty-nine days. During this time, the moon looks as if it changes size and shape. It seems to grow from a small part of a shining circle into a full circle. Then it becomes small again. The moon doesn't really change. It is just because we see different parts of it lit up by the sun.
单选题 The sun shines because it ______.
  • A. gets light from the moon
  • B. is made of glowing gases
  • C. travels around the earth
【正确答案】 B
【答案解析】[解析] 太阳发光是因为它是由燃烧的气体构成的:The sun shines because it is made of glowing gases.
单选题 While the moon travels around the earth, it ______.
  • A. shines with its own light
  • B. doesn't get light from the sun
  • C. seems to change shape
【正确答案】 C
【答案解析】[解析] 当月亮围着地球运转的时候,它的形状在变化:The moon travels around the earth about every twenty-nine days.During this time,the moon looks as if it changes size and shape.
单选题 The moon seems to change size and shape because ______.
  • A. it gives off different amounts of light
  • B. part of it bums up
  • C. we see different parts of it
【正确答案】 C
【答案解析】[解析] 我们看到月亮的形状在变化,主要是因为我们看到的是被太阳照亮的不同部分: It is just because we see different parts of it lit up by the sun.