Answer:
Physical characteristics.
Explanation:
She knew what type of birds they were based on their physical characteristics.
She didn't see their nests, or see them eat, and she didn't test and analyze their genetics, so a is the correct option.
A check that has been paid is called a cashiers check
It’s a higher fertility rate high rate of industrialization and longer life expectancy
Blocking, covering, obscuring, hiding, concealing, veiling, shrouding, darkening, extinguishing, shading, dimming, declining, diminution, extinction, penumbra