Question Focus: The diagram shows plants growing at the top of the vertical flow system. We need to label what plant this is.
Correct Answer: J
Passage Reference: A vertical flow (downflow) reed bed is a sealed, gravel filled trench with reeds growing in it.
Why this is correct: The diagram shows plants at the top of the system. The passage clearly says the trench has reeds growing in it, so the correct label for the plant is reed.
Common Mistake: Some students choose reed beds because they see the word "reed" in the passage. But the diagram label points to the plant itself, not the whole system. This is a context shift trap.
Paraphrasing: Passage: 'reeds growing in it' = Diagram: 'plant at the top'
Tips: Check carefully whether the label points to a thing, a layer, or the whole system.
Key Vocabulary:
- reed = wetland plant
- trench = long narrow hole
Question Focus: The diagram shows the first layer the wastewater flows through below the surface.
Correct Answer: E
Passage Reference: In vertical flow reed beds, the wastewater is applied to the top of the reed bed, flows down through a rhizome zone with sludge as a substrate,
Why this is correct: The diagram label is for the material in the rhizome zone. The passage tells us this zone has sludge as a substrate, so the answer is sludge.
Common Mistake: Many students choose sand because sand is also mentioned soon after. But sand belongs to the next layer, not this one. This is a wrong section trap.
Paraphrasing: Passage: 'sludge as a substrate' = Diagram: 'material in this layer'
Tips: Follow the flow direction step by step. Each layer matches the passage order.
Key Vocabulary:
- sludge = thick waste material
- substrate = base material
Question Focus: The diagram points to the layer below the sludge zone.
Correct Answer: F
Passage Reference: flows down through a rhizome zone with sludge as a substrate, then through a root zone with sand as a substrate,
Why this is correct: After the sludge layer, the passage says the water moves through a root zone with sand as a substrate. This matches the diagram position, so the answer is sand.
Common Mistake: Some students pick gravel because it is also a drainage material. But gravel comes later, after the sand. This is a sequence trap.
Paraphrasing: Passage: 'sand as a substrate' = Diagram: 'material in this middle layer'
Tips: When labeling layers, always check what comes before and after in the passage.
Key Vocabulary:
- root zone = area around roots
- flows down = moves downward
Question Focus: The diagram shows the drainage layer near the bottom of the system.
Correct Answer: B
Passage Reference: followed by a layer of gravel for drainage,
Why this is correct: The passage clearly says there is a layer of gravel for drainage before the final collection system. This matches the diagram label, so the answer is gravel.
Common Mistake: Students sometimes choose large stones here. But large stones are part of the under drainage system below the gravel. This is a partial truth trap.
Paraphrasing: Passage: 'layer of gravel for drainage' = Diagram: 'drainage layer'
Tips: Look for purpose words like "for drainage" to match the correct layer.
Key Vocabulary:
- gravel = small stones
- drainage = removal of water
Question Focus: The diagram labels the depth of the vertical reed bed.
Correct Answer: G
Passage Reference: The reeds in a downflow system are planted in a bed 60cm deep.
Why this is correct: The diagram asks for the depth measurement. The passage states the reeds are planted in a bed 60cm deep, so the correct label is 60cm.
Common Mistake: Some students choose 100m because they remember a number from earlier. But 100m refers to the length of a horizontal reed bed, not this system. This is a wrong section trap.
Paraphrasing: Passage: '60cm deep' = Diagram: 'depth of the bed'
Tips: Be careful with numbers. Always check which system the measurement belongs to.
Key Vocabulary:
- deep = how far down
- planted = put into the ground
General Tips:
- Diagram labels usually follow the passage order. Read from top to bottom.
- Pay close attention to layers and sequence words like first, then, followed by.
- Numbers are common traps. Check what each measurement describes.
- If two options seem similar, re-read the exact sentence in the passage.
