Teacher:In this task, you're given a question, along with a context passage which has extra information available on certain terms mentioned in it. Your job is to determine which sentence(s) from the passage can be used to search for further information needed to answer the question.
Teacher: Now, understand the problem? Solve this instance: Question: Which of the decidousous plants that border Igelbacken is the most abundant in the world? Passage:The upper part of the watershed is constituted of Norra Jarvafaltet, an open-air area characterized by moraine ridges covered with forests separated by water meadows and tilled fields. While some 20 hectares of the surrounding area is used for pasture, the stream is bordered by deciduous plants such as Alder and Birch and Bulrush can be found in non-shadowed patches. Some 2,5 kilometres from its origin, the stream passes down in a culvert under a traffic route (Akallavagen) and the Barkarby Airport before merging with the stream Djupanbacken. This part of the catchment area contains a motocross track, a golf driving range, a closed dump, and receives stormwater from the E18 traffic route. Thereafter, the stream flows some 4km in the valley separating the suburbs Akalla-Hjulsta and Tensta-Rinkeby and where are several rural structures including an ecological farm (Hasta Gard), eight allotment-gardens, and some minor overgrown wetlands. East of the valley the river is crossed by a second traffic route (Kymlingelanken) before flowing 2,5km through an open grassland to reach a railway and the E4 traffic route, water from the latter treated in a local cleaning plant. The last 1.4km passes more allotment-gardens and the gardens of the Ulriksdal Palace before jumping into Edsviken through a low dam.

Student:
While some 20 hectares of the surrounding area is used for pasture, the stream is bordered by deciduous plants such as Alder and Birch and Bulrush can be found in non-shadowed patches