The condition of gutter oil is so rampant that the national stability apparatus started a campaign in 2011 to stamp out the "4 black pests" (打四黑除四害) — black workshops, black factories, black markets and black gambling dens. There was a little drilling to insert cables but any dust was cleaned https://directmysocial.com/story4583019/little-known-facts-about-cctv-installation-in-wakefield