Like __, Always Happening in a Regular, Exact Way
Puzzle 2 of Aquarium Easy Pack
Question is: Like __, Always Happening in a Regular, Exact Way
and the answer is: CLOCKWORK
Word Meaning:
CLOCKWORK — A mechanism powered by a coiled spring and regulated by some form of escapement; the power is transmitted through toothed gearwheels and used to drive a mechanical clock, toy, or other device.
Definitions from Wiktionary.