Hello. You did not inform which article this question refers to, which prevents it from receiving an exact answer, however, I will try to help you in the best possible way.
When a student eats properly, receiving appropriate energy from food, that student has optimal health. This allows the student to be more attentive, willing, more proactive within the school, without appearing sleepy or lacking energy. In this case, an author who wants to show how school meals have improved students' health, should show this type of improvement as evidence of his statement.
"Vague terror" is terror that has no clear cause; as such, it is all-encompassing.
Usually terror is directly caused by something. For example, someone might have a terror of heights, crowds, or spiders. In these situations, the source of one's terror is clear, and avoiding the trigger (heights, crowds, spiders) is generally easy to do.
If terror were to have a clear source, it could be easily defined (and therefore easily combatted). When terror is vague, however, it cannot be easily defined (and cannot be easily defeated). Therefore, "vague terror" is much worse.
<span>French withdrawal from Rome in 1870.</span>
