it allows for nutrients to come into the cell using passive tranport aka moving anything on a gradient without the use of energy (ATP).
There are a couple features unique to mammals, here are some:
1. Mammary Glands- evolved from modified sweats glands, these are used to create milk for offspring. Only females produce this milk.
2. Hair- this is an adaptation that provides insulation to keep the animal warm, provide protection of the skin, and sometimes camouflage the animal through the hair's color patterns.
3. Sweat glands- while being unique to mammals, they are not present in all of them. For example, whales do not have sweat glands at all because they live in the ocean!
Answer:
Air speed of bird is 
mph
Explanation:
let the speed of the bird in still air be "X"
Speed of the bird when it flies in the direction of flow of wind 
Speed of the bird when it flies in the opposite direction of flow of wind 
The total time taken is equal to 
minutes
hours
The distance in miles is equal to 
miles
On solving the above equation, we get -
Air speed of bird is mph
Given that,
Density of the liquid, d = 3 g/ml
Volume, V = 20 mL
To find,
The mass of the liquid.
Solution,
The density of an object is given by its mass divided by volume such that,
d = m/V
m is mass
m = d×V
Put all the values,
m = 3 g/mL × 20 mL
= 60 grams
Hence, the mass of a liquid is 60 grams.
Environmental science is the study of interactions among the physical, chemical and biological components of the environment. Environmental science enlightens us on how to conserve our environment in the face of increasing human population growth and anthropogenic activities that degrade natural resources and ecosystems.
