CFCs are Chlorofluorocarbon substances used in refrigerants (subtances used to keep other things cold) and in aerosol products.
they are both relatively nontoxic(nonpoisonous) and nonflammabale - at least as compared to alternatives.
They are rather volatile - they are not very stable. Therefore it does not make sense to say that they are strong - the correct answer is then strength.
Wings of a windmill, because they’re producing energy.
