The answer is A, vinegar and soda. Let me know if you need an explanation :)
The correct option is:
crest trough
In fact, the sentence can be completed as follows:
"The amplitude of a wave is the height of a wave as measured from the highest point on the wave crest to the lowest point on the wave trough."
<span>a=8(m/<span>sec2</span>).. i answered this earlier i think.</span>
Hydrogen and then its helium
