Name The Year: Harold Wilson resigns as British PM.?

Questions

Common name for certain mammals in the mole family that lead a semiaquatic existence beside ponds & streams, feeding on insects, fish, & mollusks?

Common name for certain marine members of a family of venomous snakes?

Common name for certain members of a family of venomous snakes, known for their intimidating behavior & deadly bite?

Common name for certain slow-moving arboreal mammals that inhabit the tropical forests of south & central america?

Common name for certain small, burrowing mammals characterized by a pointed snout; rudimentary eyes; soft, thick, velvety fur; short legs; broad feet; & long, powerful claws on the front pair of legs?