Question text
18 The sentences describe sound waves. Three words have been omitted. Sound waves are longitudinal waves that consist of regions of higher pressure called ......1...... and regions of lower pressure called ......2...... . An echo occurs when a sound wave is ......3...... . Which words complete gaps 1, 2 and 3? 1 2 3 A compressions rarefactions reflected B compressions rarefactions refracted C rarefactions compressions refracted D rarefactions compressions reflected
18 The sentences describe sound waves. Three words have been omitted.
Sound waves are longitudinal waves that consist of regions of higher pressure called ......1......
and regions of lower pressure called ......2...... .
An echo occurs when a sound wave is ......3...... .
Which words complete gaps 1, 2 and 3?
1 2 3
A compressions rarefactions reflected
B compressions rarefactions refracted
C rarefactions compressions refracted
D rarefactions compressions reflected
Select your answer: