Reading is an inexpensive hobby; For example, the library is free.
Answer:
They probably won't exist anymore. There would be another form of technology that replaces phones.
Or you could say in 20 years, phones will probably be able to transform into other stuff like computers etc.
Explanation:
The correct answer to the question that is being presented above would be letter D. The sentence that does not contain any punctuation errors is 'Trout, mullet, and sea bass swim here; but Erin, Terri, and I are after crabs.'.