Priorities
Priorities
[A teacher is talking to a student, sitting at a desk.] Teacher: If you don't turn in at least one homework assignment, you'll fail this class. [The student holds up his report card.] Student: Yeah. But if I can fail this class, the grades on my report card will be in alphabetical order!

In this comic, Cueball is a student, who apparently didn't turn in his homework assignment repeatedly, for which he gets a warning from his Cueball-like teacher.
In some schools in the United States, a student's grades are determined mainly using letters for quick reference. In most schools, the letter grades are given as follows:
A — 100%–90% B — 89%–80% C — 79%–70% D — 69%–60% F — 59%–0%
Traditionally, these schools send ' report cards ' in which the student's current grading of the semester or even the entirety of the class the student is taking is denoted using these letters, for example:
English — A Mathematics — D Science — B Social Studies — B World Building — C
The student may have noted that, if he aims for certain scoring (for example: altering the quality of his homework or even sending out his homework only at the times needed for his grades to reach a certain level), he could make the report card spell every letter grade in alphabetical order. Deriving from the previous example, the student would aim for the following report card:
English — A Mathematics — B Science — C Social Studies — D World Building — F
Interestingly, since in some schools even a 0% grade would produce the required 'F' grade, the student does not need to work at all (not even turn in any school assignments) to get the required 'F' grade, this leading to the situation presented in the comic above. Rather than a letter upon a continuum (as it might be assumed if 'E' were not skipped) it is generally accepted that 'F' actually stands for 'Failed' and covers any situation where insufficient credit was gained to obtain any other letter-grade. There are some schools, though, where turning in nothing would result in the class being marked "incomplete" or "inc" instead of having a grade shown at all.
The title text references that, not only can the grades in the report card inadvertently spell out certain words (for example: 'CAB' or 'FAD'), but also that the letter grade system denoted omits the letter 'E' in standard letter grading. The reason for the missing "E" is complex and explained in this Slate article . However, this is not universal in the United States: Ohio State University, for example, uses 'E' for failing.
[A teacher is talking to a student, sitting at a desk.] Teacher: If you don't turn in at least one homework assignment, you'll fail this class. [The student holds up his report card.] Student: Yeah. But if I can fail this class, the grades on my report card will be in alphabetical order!
