plural of active volcano

plural of active galaxy

plural of beehive of activity

plural of catalytic activity

plural of optical activity

(psychology) Aimless, often self-comforting behavior displayed when in doubt, blocked or frustrated. / (more broadly) Something done needlessly when procrastinating.

plural of activity stream

(Internet) A list of recent activities performed by an individual, typically on a particular website.

plural of extravehicular activity

plural of activated sludge