Since this is an open question with no choices, I am answering with what I think will best fill in the blank. Note: I do not know exactly what answer they are looking for.
The best answer is: REM
REM is the stage of sleep where dreaming occurs. REM stands for Rapid Eye Movement. Exactly as the title says, REM sleep is characterized by fast back and forth movement of the eyes.
Answer and Explanation:
The following is an idea/example on how to write about this topic:
Write about what is your idea of a happy school where learning is an engaging and joyful activity.
I imagine such a school to give autonomy to students. They are taught from an early age to manage their own choices and the time they will dedicate to studying. For instance, students could choose which subjects to study that semester. Teachers would then present them with ideas on how to get started, on which topics there are to be seen at the level for that subject, etc. Students and teachers would then agree on how much time would be applied to each topic. Students would study with the help of peers as well as of teachers. However, teachers would be more like guides than authority figures.
The middle of the 20th century was considered to be the "golden age of food processing", as what was coined by Harvey Levenstein, because the American believed at that time that "processed foods made them life easier." To add up, these methods of processing meat and freezing was one of the scientific innovations achieved at that time.
