Question: Both Greenhill and Waterfall Gully are both suburbs of what city?

Context paragraphs:
Cleland Conservation Park: Cleland Conservation Park is a protected area located in the Adelaide Hills, South Australia about 22 km south-east of the Adelaide city centre.  Cleland Conservation Park conserves a significant area of natural bushland on the Adelaide Hills face and includes the internationally popular "Cleland Wildlife Park" and the popular tourist destinations of Mount Lofty summit and Waterfall Gully.  It is maintained by the South Australian Department of Environment, Water and Natural Resources (DEWNR).

Langman Reserve: Langman Reserve is a large reserve situated in the Adelaide foothills between the suburbs of Burnside and Waterfall Gully, South Australia.  It was converted from a quarry in the late 1960s, and is named after a former mayor of the City of Burnside.

Chambers Gully: Chambers Gully is an offshoot of Waterfall Gully in the Eastern Suburbs of Adelaide, South Australia.  It used to be a local landfill but in the past decade has been reclaimed as a park by volunteer work.  It contains a number of old ruins, walking trails, springs and is an excellent place to spot local wildlife such as koalas.

Eagle On The Hill, South Australia: Eagle On The Hill is an unbounded locality of Adelaide in the Adelaide Foothills.  It borders Mount Osmond and Waterfall Gully.

Greenhill, South Australia: Greenhill is a suburb of Adelaide located about 9.3 km east of the city centre in the foothills of the Adelaide Hills.  Its boundaries were created in October 2001 in respect of the “long established name” with some land being moved into the adjoining suburb of Waterfall Gully in July 2002.  The suburb includes Greenhill Recreation Park and the western slopes of Mount Lofty.  Greenhill Creek flows through Waterfall Gully and feeds into First Creek.

Waterfall Gully, South Australia: Waterfall Gully is an eastern suburb of the South Australian capital city of Adelaide.  It is located in the foothills of the Mount Lofty Ranges around 5 km east-south-east of the Adelaide city centre.  For the most part, the suburb encompasses one long gully with First Creek at its centre and Waterfall Gully Road running adjacent to the creek.  At the southern end of the gully is First Falls, the waterfall for which the suburb was named.  Part of the City of Burnside, Waterfall Gully is bounded to the north by the suburb of Burnside, from the north-east to south-east by Cleland Conservation Park (part of the suburb of Cleland), to the south by Crafers West, and to the west by Leawood Gardens and Mount Osmond.

Hukou Waterfall: The Hukou Waterfall (), is the largest waterfall on the Yellow River, China, the second largest waterfall in China (after the Huangguoshu Waterfall), and the world's largest yellow waterfall.  It is located at the intersection of Shanxi Province and Shaanxi Province, 165 km to the west of Fenxi City, and 50 km to the east of Yichuan where the middle reaches of the Yellow River flow through Jinxia Grand Canyon.  The width of the waterfall changes with the season, usually 30 m wide but increasing to 50 m during flood season.  It has a height of over 20 m .  When the Yellow River approaches the Hukou Mountain, blocked by mountains on both sides, its width is abruptly narrowed down to 20 m - 30 m .  The water's velocity increases, and then plunges over a narrow opening on a cliff, forming a waterfall 15 m high and 20 m wide, as if water were pouring down from a huge teapot.  Hence it gets the name "Hukou" (literally, "flask mouth") Waterfall.

Electoral district of Bragg: Bragg is an electoral district of the House of Assembly in the Australian state of South Australia.  The seat of Bragg is named after the eminent physicists Bragg – William Henry and his son, William Lawrence.  The electorate is largely urban and encompasses a significant portion of the City of Burnside, stretching from the east parklands of Adelaide into the Adelaide Hills.  After a redistribution following the 2006 election, the boundary moved eastwards to include suburbs that had formerly been in the seat of Heysen and now borders Kavel.  Bragg currently includes the metropolitan suburbs of Beaumont, Burnside, Dulwich, Erindale, Hazelwood Park, Heathpool, Kensington Park, Leabrook, Linden Park, Rose Park, Marryatville, Skye, St Georges, Stonyfell, Toorak Gardens, Tusmore, Wattle Park and parts of Glen Osmond, and in the hills it includes Crafers, Cleland, Greenhill, Mount Osmond, Piccadilly, Summertown and parts of Ashton, Basket Range, Carey Gully, Horsnell Gully, Leawood Gardens and Uraidla.

Division of La Trobe: The Division of La Trobe is an Australian Electoral Division in the state of Victoria.  It is located in the outer eastern/south-eastern suburbs of Melbourne.  It was originally located closer to the city, but redistributions moved it further south-east.  It originally included the suburbs of Croydon, Dandenong, Ferntree Gully and Ringwood.  As of 2005, the division is roughly Y-shaped, centred on the Cardinia Reservoir.  It includes the suburbs of Boronia, Belgrave and Ferntree Gully in the north-west, the suburbs of Berwick, Beaconsfield and Officer in the south, and the towns of Gembrook, Emerald and Cockatoo.

Mount Osmond, South Australia: Mount Osmond is a small suburb of 2,497 people in the South Australian capital city of Adelaide.  It is part of the City of Burnside local government area and located in the foothills of the Adelaide Hills, five kilometres south east of the city centre.  The suburb is high on the hill of the same name, which is the last hill on the right when approaching Adelaide down the South Eastern Freeway before the road levels out onto the Adelaide Plains.  It is bounded to the north by the suburb of Beaumont, to the north-east by Burnside, to the east by Waterfall Gully, to the south by Leawood Gardens/Eagle On The Hill, to the south-west by Urrbrae, to the west by Glen Osmond and to the north-west by St Georges.

Supporting paragraphs: Greenhill, South Australia Waterfall Gully, South Australia
Answer: Adelaide