Never heard tidewater and fall line, only piedmont. It must be a Mandela Effect.
Certainty means a firm conviction that something is the case.
Answer:
Information from the Internet is b. a good source for research material.
Explanation:
The Internet has become the most important source of information for those people who need to conduct research on a given topic. Although not all the information is reliable, the wide variety of sources and the immediacy that characterizes Internet services allow any person who is willing to investigate something to compare thousands of sources and select the material they consider suitable. Therefore, sentence B is the correct answer.
