There are huge mountains covered with large forests, and wide, irrigable plains with navigable rivers.巨大的山脉都覆盖着森林, 广阔 、 可灌溉的平原带有适于航行的河流....

adj.可灌溉的...

irrigable的音标：irrigable的英式发音音标为：['ɪrɪgəbl]irrigable的美式发音音标为：['ɪrɪgəbəl]...