. These gases let in light but keep heat from escaping, like the glass walls of a greenhouse. First, sunlight shines onto the Earth's surface, (1) ________  it is absorbed and then radiates back into the atmosphere as heat. This is because as the Earth's average temperature climbs, winds and ocean currents move heat around the globe in ways that can cool some areas, warm (2) _______, and change the amount of rain and snow falling. (3) _______, the climate changes differently in different areas.

Question 1. A. which                       B. where                     C. that                             D. which

Question 2. A. others                       B. another                   C. one                             D. the other

Question 3. A. However                  B. In addition             C. On the contrary          D. As a result