Clucked is the past tense of cluck, for example "the chickens clucked as they scratched around the yard".
A duct is any kind of tube or pipe that carries gas or a liquid. Ducts are most commonly used for ventilation, like an air conditioning system.
You instruct someone when you tell them what to do in small, helpful steps. The man in the picture is instructing the woman. See also instructions.
Something is plucked if it has had all the hair or feathers pulled out of it. Plucked is also the past tense of pluck.
Sucked is the past tense of suck, for example "the girl sucked her drink through a straw".
Tucked is the past tense of tuck. The sheets on the bed in the picture are tucked in, and have all the loose ends nicely hidden away.