Answer from cs61c-eb (Dae-Yeon Kim 16568138) for Question 2
microwave, rice cooker, alarm clock.
even though microwave and rice cooker don't have constant timer, yet they have distinct states, and
need to switch states depending on what time it is
mainly from some type of cooking mode to turning off.

Alarm clock has two distinct states, when alarm goes off and when alarm doesn't go off.
When the clock hits the designated time, it will switch the states for certain amount of time, and the alarm will be silenced.