阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。

The Budj Bim Cultural Landscape has long been regarded as a wonder of ancient engineering. The water system in Australia【小题1】 (build) more than 6, 000 years ago—long before even the Egyptian pyramids took shape.

Ancient inhabitants of the region made the system of channels and dams as an【小题2】(extraordinary) complex trap for the eels(鳗鱼) that locals depended on for food. Budj Bim was recognized as【小题3】World Heritage site today, but few suspected the system ran so far and so deep.

In fact, it took a disaster for Budj Bim【小题4】(reveal) itself in all its former glory. Bushfires,【小题5】(spark) by record temperatures and lasting drought, have burned away the thick leaves covering the water system,【小题6】(allow) the full scale of Budj Bim to emerge from the flames.

The Egyptian pyramids were made with materials that were plentiful nearby, and【小题7】was Budj Bim. It was made with the area’s most ready resource: volcanic rock. Those building blocks came from the lava of a now-inactive volcano,【小题8】 the ancient people used to redirect waters from Lake Condah—waters heavy with eels.

Now the Aboriginals still call parts of the area home, and their population【小题9】(decline) dramatically since Europeans arrived on the continent. But their【小题10】(achievement) stand the test of time—even if it took a tragedy to reveal them. It’s an important acknowledgement of the work their ancestors have done.