1 . The secrets of Ancient Maya civilisation are powerful among people. Maya civilisation     1    （surround）by mystery since its rediscovery in the 19th century. The Maya built     2    （impress）palaces and temples, including their representative step pyramids. But the greatest mystery of all is what caused the Maya     3    （abandon）most of their great cities. Some research seems to indicate that the Maya people themselves may have played     4    part in their downfall. Owing to the     5    （change）landscape, it is possible that the Maya people unknowingly reduced their     6    （able）to deal with natural disasters. Research also suggests that those natural disasters may have led to the decline     7    the Maya. These droughts would have led to food shortages, conflicts and, ultimately, the downfall of the cities.     8     the reasons, Maya civilization     9    （large）disappeared within the deep jungle. Its once-great cities fell into ruin,     10    （leave）various mysteries for later people to solve. Meanwhile, the rise and fall of this civilisation must also leave us thinking about our own past, present and future.