How can you tell if someone sent you a text message to your email instead of a email

Melissa needs to add a topic to an email that she will send to her teacher. choose the name of the field where she should type her topic.

Apython programming question: assume s is a string of lower case characters. write a program that prints the number of times the string 'bob' occurs in s. for example, if s = 'azcbobobegghakl', then your program should print number of times bob occurs is: 2

What are "open-loop" and "closed-loop" systems