Compound a is a
amine.
compound b is a
amine.
compound c is a
amine.
compound d is
.

answer: you could do some invislibe ink.

explanation: i will tell you how to if u answer my question.

why is arctic sea ice important? arctic sea ice keeps the polar regions cool and moderate global climate. sea ice has a bright surface; 80 percent of the sunlight that strikes it is reflected back into space. as sea ice melts in the summer, it exposes the dark ocean surface.