Answer: "Since we hoped to get a later curfew over the weekend, we offered to do the dinner dishes" is a complex sentence.
Step-by-step explanation: A complex sentence is a sentence made up of one or more independent clauses and at least one subordinate clause. Unlike an independent clause, a subordinate clause cannot stand alone as a sentence because it does not express a full idea. Moreover, a subordinate clause is always introduced by a subordinating conjunction. The sentence "Since we hoped to get a later curfew over the weekend, we offered to do the dinner dishes" is a complex sentence because it includes a subordinate clause ("Since we hoped to get a later curfew over the weekend") and an independent clause ("we offered to do the dinner dishes"). Furthermore, the subordinate clause has been introduced by the subordinating conjunction "since", which expresses a cause.