Biology class. They had worksheets to complete.
A student raised her hand. Question #5 was illegible, and she wanted my help in deciphering it.
It wasn't a terrible copy. The teacher had shrunk down the pages so that four worksheets fit on one sheet of paper (2 on front and 2 on back). It was kind of clever, especially considering the budget woes of the schools.
What I could read of the question: "How do enzymes weaken the (illegible) in sub..." (and I couldn't read anything after that).
I figured out that the last word had to be substances, mainly because the student had her notes out, and enzymes and substances were prominent on that page. But the other word had me stumped.
Less than five minutes later, another student figured it out. The word had to be "bonds". Okay, then.
The next period, another student asks the same question. This time I could rattle it off: "How do enzymes weaken the bonds in substances?"
Subbing trick #2: Students tend to ask the same questions every period. If you can figure out the answers with the first group, you're set for the day.