When an ecosystem changes, the results are . a. all positive
b. all negative
c. neither positive nor negative
d. mixed between positive and negative

Your answer is d. silli hope this ! : ) i left an explanation down below if you need it: a sill forms when hot magma squeezes between layers of rock to form a hardened sheet of rock. a sill is basically a tabular sheet intrusion between old layers of sedimentary rock, volcanic beds, or in the direction of foliation inherent in metamorphic rock. the word sill means a concordant intrusive sheet.

Pretty ssure the answer re her answer is b hope this : )