If you are not using an eyebrow transarency map, you need to make sure that the eyebrow's specular colour is true black, and ensure that transparency and transparency edge are set to 1 in the material room. To get rid of them with morphs, you need to have the morph packs from DAZ. In the !V3 Features will be a BrowsGone_INJ pose which you can use to remove the eyebrows.