For a stationary observer, when the source of a sound is moving , its A- Amplitude increase
B- pitch appears to change
C- Speed increases
D- decibel level decreases

the answer would be 2, if crossing over doesn’t occur 2 out of 4 of the daughter cells will have that allele.

hope this : )

1. efficient use of space

2. elimination of groundwater contamination

3. energy generation

4. lower carbon footprint