Answer:
1. cx 2. S 3. Cd 4.cx 5. cx 6. cx 7. Cd
Step-by-step explanation:
Look for verbs, the main element in a predicate. If there is only one verb, the sentence is simple. #2 has only one verb: testifies. It is the only simple sentence.
When there are two or more verbs, check for conjunctions. And, but & or are the most common coordinating conjunctions which also may include yet, so, for & nor. These join independent clauses to form compound sentences.
Sentence #7 has two verbs: fell and propose, each in an independent clause joined by the conjunction yet. It is the only compound sentence in this set.
"So that" joins two independent clauses in sentence #3 to create a compound sentence, but that some may argue that it is a mistake because "that" also functions as a relative pronoun. (but not in that sentence)
Words like that, what, whom, who & which are relative pronouns which introduce noun clauses and relative clauses. These clauses must be connected to a main clause, and create a complex sentence. Such is the case in sentence #4. "Who" stands for 'Jesus' in the relative clause.
Subordinating Conjunctions: Though, Because, Although, Since, Whenever and a few others introduce subordinate clauses. Ironically, a perfectly good Independent Clause becomes dependent with the addition of one of those conjunctions, and must become part of a complex sentence. #1, #5 & #6 are examples.