Now identify the simple subject and simple predicate . the meeting began promptly at seven o'clock .

The simple subject of this sentence is "Meeting" and the simple predicate of this sentence is "began"

Explanation:

All sentences are made with two main parts which are subject and predicate. The simple subject is the main word of the full subject, it is always a noun or a pronoun, then from the full subject "The meeting" the main word is "meeting". The simple predicate is the complete verb without the other words of the full predicate, then "began promptly at seven o'clock ." is the full predicate and the full verb is "began".