1. Sound can travel through vacuum.   True   False   2. The part of the inner ear shaped like a snail is called the _______.   eardrum   hammer   cochlea   Hint Half-n-half Clue   3. Out of the following materials, the best conductor of sound is _______.   Steel   Water   Air   Half-n-half Clue   4. When sounds reach the _______ or tympanic membrane, they make it vibrate.   hammer   cochlea   eardrum   Half-n-half Clue   5. Sounds travels faster in air as compared to water.   True   False   6. The approximate speed of sound in air is _______ m/s.   1600   5000   3 × 108   330   Half-n-half Clue   7. Echoes are caused by _______ of sound.   refraction   rarefaction   reflection   Half-n-half Clue