A conpound-complex sentence is two subordinate clause,independent clause. sentences joined with a coordinating conjunction
example: Since I had time,I went to the store,and when I returned,I out the groceries away.
The answers should be C and D
Because petroleum-based plastics like PET don't decompose the same way organic material does. Wood, grass and food scraps undergo a process known as biodegradation when they're buried, which is a fancy way of saying they're transformed by bacteria in the soil into other useful compounds.
