The correct answers are 1) complex sentence; 2) compound-complex sentence; and 3)compound sentence.
Explanation:
The first sentence is a complex sentence, meaning that it contains an independent clause (a complete though) and at least one subordinate clause (cannot stand alone even if it has subject and its predicate); a compound-complex sentence has at least two independent clauses as well as one dependent; finally, a compound sentence has two independent clauses with similar ideas; connectors or comas or semi colons can be used to put them together.
