Answer:
Complex sentence
Step-by-step explanation:
Complex sentence is composed of one independent clause and at least one dependent clause.
Since it takes approximately one thousand years for a used printer cartridge to decompose, recycling these plastic ink dispensers helps the environment. This sentence has one independent clause which is 'recycling these plastic ink dispensers helps the environment' and an adverb clause i.e. 'since it takes approximately one thousand years for a used printer cartridge to decompose'.