Answer:
Biomagnification
Explanation:
DDT is one of the prime examples of a substance that biomagnifies. I would familiarize yourself with this topic. Hopefully this is a helpful starting point.
Answer:
T=26.03 N
Explanation:
Given that
Distance between poles = 12 m
Mass of block m= 4 kg
Sag distance = 5 m
Lets take tension in the clothesline is T.
The component of tension in vertical direction will be T cosθ.
By force balancing
2 T cosθ = 40
here 
θ=39.80°
2 T cos39.8 = 40
T=26.03 N
Well YOU cant make your questions verified. if theres more than one answer to the question the person who asked the question will choose the best answer. usually based upon like how well it explains and if its the right answer