Why is it sometimes difficult to link cause and effect in regard to some pollutants (such as pesticides)

i got something better   a catchphrase here it is

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what the squwock

explanation:

after receiving a stimus, the sensory receptors send(s) signals to the appropriate area of the body.  

the must be sensory neurons.  

hope its .

the answer is: metamorphic rocks often show the presence of fossils, also a

hope i

-lavira: )