Calvin and Hobbes by Bill Watterson for March 29, 1989
Susie: There's the bell. We've got to go to class. Calvin: Rats. I didn't get 50 bugs yet. Susie: What do you have? Calvin: One drowned worm, a piece of fuzz lint that looks like a bug, a live ant, and a smashed fly. Susie: Well, if you label them scientifically in the next 30 seconds, maybe you'll get an "F+." Calvin: We've got to label these too?!? I was just going to put them all in an envelope. Susie: Actually I don't think there's any way you'll get an "F+." Calvin: For all this work, I'd better at least get a "D."