Question

which type of sentence is this? since it takes approximately one thousand years for a used printer cartridge to decompose, recycling these plastic ink dispensers helps the environment. simple compound complex compound-complex

Explanation:

A complex sentence contains one independent clause and at least one dependent clause. The given sentence has an independent clause ("recycling these plastic ink dispensers helps the environment") and a dependent adverbial clause introduced by the subordinating conjunction "Since" ("Since it takes approximately one thousand years for a used printer cartridge to decompose").

Answer:

complex