(1) At the edge of the marsh behind our middle school, the cattails stand like crowded pencils, and red-winged blackbirds balance on them as if the wind is a moving sidewalk. I began visiting the marsh after science club, mostly because it was quieter than the cafeteria and because my teacher, Mr. Duran, said it was "an outdoor laboratory."
(2) The first week of October, I noticed something unsettling: the water level had dropped, leaving a muddy ring around the pond like a bathtub stain. The frogs that usually chirped at dusk were silent. When I stepped closer, my shoe sank, and a sour smell rose from the exposed mud.
(3) Mr. Duran explained that wetlands act like natural sponges. They absorb rainwater and release it slowly, which helps prevent flooding. They also filter pollution, trapping dirt and chemicals so cleaner water can flow downstream. However, he added, a wetland can only do those jobs if it stays wet.
(4) We checked the rain records from the town website. September had been unusually dry, and the creek that fed the marsh was running thin. Meanwhile, a new parking lot was being built uphill. The construction crew had cleared trees and packed down soil, so when it finally rained, the water would rush off the hard ground instead of soaking in.
(5) "So the marsh is losing water from two sides," I said, trying to connect the clues. Mr. Duran nodded. "Less rain coming in, and less land to hold what does fall," he replied. Consequently, the marsh dried faster than it used to.
(6) The next day, I brought a notebook and sat on a fallen log. A dragonfly landed on my pencil and held still, its wings shining like thin glass. I wrote down what I saw, but I also wrote down what I didn't see: fewer frog calls, fewer ripples, fewer footprints of birds. It felt strange to count absences, yet that was part of observing.
(7) By late October, a storm arrived and the marsh filled again. The frogs returned, and the cattails looked less tired. Still, I kept thinking about the muddy ring. It was like a warning line, showing how quickly a place can change when weather and human decisions collide.
According to the passage, what caused the marsh to dry faster than it used to?
- The thin creek carried extra chemicals into the marsh, and Mr. Duran said pollution slowly poisoned the water until it evaporated away.
- Unusually dry weather and nearby construction cut the water entering and staying in the marsh. (correct answer)
- The frogs and blackbirds crowded the pond so heavily that their daily activity used up much of the marsh's shrinking water.
- Mr. Duran and the science club drained part of the pond on purpose to study the muddy soil at the bottom.
Explanation: The passage points to two causes working together: September had been "unusually dry," so less rain fed the marsh, and the new uphill parking lot let rainwater "rush off the hard ground instead of soaking in." The narrator sums it up as "losing water from two sides," which matches the answer naming dry weather and nearby construction. The choice about chemicals poisoning the water misreads paragraph 3—Mr. Duran says wetlands filter pollution, but he never says pollution dried the marsh. The choice blaming frogs and blackbirds is wrong because the passage says the frogs were silent and their numbers dropped as the water fell; the animals did not use up the water. The choice about Mr. Duran and the club draining the pond misreads "outdoor laboratory"—they observed the marsh and even celebrated when the storm refilled it, so they never drained it. Only one choice names the two real causes the passage actually gives.