1. D AILY Q UESTIONS D EC. 9 TO D EC. 13 Dec. 9 What are some possible uses of infrared rays? a. Cancer treatment b. Communication c. See inside people d. Remote controls and cameras

2. D EC. 10 These are all uses of microwaves except A. detecting echoes B. in cellular C. see inside your luggage D. cause water molecules to vibrate

3. Dec. 11 Dangers of radio waves include a. Listening to too much radio b. Leukemia c. Overheating d. High frequencies

4. D EC. 12 In the following four situations, heat moves through matter. In which situation was the process of conduction responsible for most of that movement? A. a radiator heated with hot water warms a room B. The person sitting closest to the fire finds it necessary to move farther from the heat C. The handle of a cast iron skillet being used to cook something becomes too hot to touch. D. The red-hot coil of an electric space heater is used to keep a small room warm

5. D EC. 13 If Bob lets the room cool down by opening both the top and the bottom of his window, what is the best explanation for why this works? A. air comes in the top to cool the ceiling and in the bottom to cool the floor B. Cooler air comes in the bottom of the window, and warm air goes out the top. C. Warmer air goes out through both the bottom and the top of the window. D. Cooler air comes in through both the bottom and the top of the window.