Reading Comprehension · Science
PrepTest 122 · Section 3 · Passage 4
Questions 21–27
Before you start
Open PrepTest 122, Section 3 in your official copy from LSAC and read the passage for Questions 21–27, using the structure guide below. The passage is not reprinted here.
Structure guide
- P1: describes a large effect, names its basic cause, poses a question, and says science has answered it
- P2: explains a general process shared by every member of a group, then a natural hindrance to it
- P3: describes a special mechanism some members developed to dodge the hindrance, then ties it back to the effect
Step 2 · The kid passage
Why the Four-Pack Stands Sell So Much Lemonade
Every block that adopted the two-table lemonade stand was changed by it. Kids on Maple Street started staying outside all summer, and the block party grew huge, partly thanks to these stands and partly thanks to Aunt Rosa's popsicle cart. The main reason is speed: a two-table stand pours far more cups per hour than any other setup, and the first kids to use it noticed right away. But why are these stands so fast? Priya's stopwatch study finally found out.
Every stand squeezes lemons, splitting them into juice and peels. The juice goes into the pitcher, and the peels get tossed into the yard. Then the stirrer mixes sugar into the juice. The stirrer is the most important kid at any stand. Sadly, when peels pile up around the stirrer compared with the sugar, which happens on any windy day, the stirrer starts grabbing peels instead of sugar, and mixing jams.
Some stands, though, have worked out a fix over many summers. They squeeze at the front table, but the stirrer sits inside a zipped-up tent at the back. The trick is that peels and everything else loose stay out of the tent. Loose sugar can't go in either, so it is first poured into little paper packets holding four spoons each, called four-packs. The packets go into the tent, get torn open, and the sugar is stirred in. That's why it's called the four-pack method. Four-pack stands, like Priya's, Nadia's, and Owen's, are the busiest on the block.
Step 4 · The courtroom tale
The Case of the Speedy Mailroom
Two fictional shipping shops in Puddleford fought over a prize for fastest sorting. The loser cried foul. Mr. Whitfield explained. "Your Honor, every shop opens boxes, keeps the letters, and tosses the packing foam. Then the sorter files the letters. But when foam drifts around the sorter, she grabs foam instead of mail, and everything jams. My client fixed that. The sorter works in a sealed back room. Nothing loose gets in, not foam, not even loose letters. So letters are first bundled into rubber-banded stacks, passed through a slot, and unbundled inside." The judge smiled. "No cheating, then. Just a clever setup that keeps the sorter's hands on the right thing."