Answer:
there r not only 2 types of nests
Cup nest.
Adherent nests.
Platform nests.
Earth-hole nests.
Ground and mound nests.
Scrape nests.
Explanation:
Because it takes LOADS of feathers to make up 1kg and lead would be such a small amount, it could fit in a purse.
Because if we're simultaneously moving/manipulating two different variables it can be very hard to determine why one variable is changing and why the other is changing. While this can be done with more complicated experimental designs, it usually is the case that scientists will only manipulate one variable and not two different ones.
The answer is D because this would help them to survive and is equal to natural selection
