Answer:
On October 1, 1949, Chinese Communist leader Mao Zedong declared the creation of the People's Republic of China (PRC).
No it is not. It is an adverb phrase since it lacks a subordinating conjunction.
Adverb clauses must be preceded or started by a subordinating conjunction such as after, if, because or although. For a sentence to qualify as an adverb clause it must include in its body a subject and a verb.
As a general rule you can use the following formula:
An adverb clause equals a subordinate conjunction plus a subject plus a verb, and it should be answering how? when? where? or why?
He thought that he knew a lot about witchcraft so he had more people arrested because he was Christian and thought when one was found the rest needed to be hunted for as well. he started the peak of it if you will
