Answer:
1.the highest point of the wave is the crest while lowest point is trough.
2.?
3. wave length
4. frequency
5. A is crest b is trough c is amplitude and d is wave length
7.a = this is longitudinal wave, b no = letter h represents a compression and letter I represents rarefactions , letter g represents a wave length.
8 . in transverse wave
9. longitudinal wave
10. longitudinal wave
11. transverse wave
12. ?