[bobtuti]

Hi everyone
I think something is not clear for sentence 38.
unstable (Adj),
faintly(adv), blurish (adj), gas (n) => adj+adv+adj + n??? this form is correct?
chemical (adj, n), active (adj, n) , i change chemical to chemically (adv)=> adv +adj + N
For me, i don't understand why B is correct, and why chemical should change chemically?
when we use the structure adv+adj?
Thanks for your support
Bob