【正确答案】 D

【答案解析】[听力原文]18-30
Perth is actually a very young city which sits on the north bank of the Swan River. I'm sure many of you have already seen it. Less than 200 years ago the entire city center was an undeveloped wetland. Perth was founded by the British as the Swan River settlement in 1829, although the Dutch had visited other parts of the state much earlier. It grew quite slowly in the beginning, mostly because it was so isolated. There were constant problems with communications, and labor was always in short supply. Then in the 1890s gold was discovered in Western Australia and Perth boomed.
Anyway, there are now around 1.4 million people living in Perth and its suburbs. The city itself has sprawled in all directions and it will take you months to see it all. It stretches from the Darling Ranges—chain of hills—n the east, to the Indian Ocean in the West. It has swallowed Perth's southern sister city, Fremantle and almost reaches the small township of Yanchep in the north.