Answer:
It says that laughter is unexpected but short-lived
Explanation:
The word "sudden" shows us that laughter is unexpected, and the image of the wave which "breaks and dies in breaking" shows us that laughter is temporary and short lived, as the laughter will eventually "break".
C.......................................
Answer:
There is less of a difference between the two groups in 2000 than in 1960.
A title you could use is The Monster Called Addiction.