The correct answer for this question is: "<span>B) kidneys clean the blood by filtering it to remove wastes." Kidneys clean the blood by filtering it and removing the waste.
The correct answer for this question is: "</span><span>A) secretes excess water as sweat." The role of the skin in the excretory system is to secrete waste and excess water as sweat.</span>
        
                    
             
        
        
        
Answer:
Explanation:
biology of your talking about life evolution but all if your talking about mankind evolution and technology
 
        
             
        
        
        
One reason is if someone is injured and needed to use pain pills, sometimes they get addicted to it
        
                    
             
        
        
        
Cell, atom, molecule, electron, proton
        
             
        
        
        
Q1. The answer is 1.
It can be calculated using the equation:
 (1/2)ⁿ = x
x - decimal amount remaining, 
n - a number of half-lives.
x = 50% = 50/100 = 0.5
n = ?
(1/2)ⁿ = 0.5
log((1/2)ⁿ) = log(0.5)
n * log(1/2) = log(0.5)
n * log(0.5) = log(0.5)
n = log(0.5)/log(0.5)
n = 1
Q10. The answer is 2.
It can be calculated using the equation:
 (1/2)ⁿ = x
x - decimal amount remaining, 
n - a number of half-lives.
Rhyolite #2 has 25% of the parent H remaining:
x = 25% = 25/100 = 0.25
n = ?
(1/2)ⁿ = 0.25
log((1/2)ⁿ) = log(0.25)
n * log(1/2) = log(0.25)
n * log(0.5) = log(0.25)
n = log(0.25)/log(0.5)
n = -0.602 / - 0.301
n = 2
Q3. The answer is 100 million years.
A number of half-lives (n) is a quotient of total time elapsed (t) and length of half-life (H):
n = t/H
n = 1
t = ?
H = 100 000 000 years
n = t/H
t = n * H
t = 1 * 100 000 000 years
t = 100 000 000 years<span>
</span>