Which two phrases in the passage demonstrate what the word boisterous means? Close by, a rock of less enormous height Breaks the wild waves, and forms dangerous strait; Full on its crown a fig's green branches rise, And shoot a leafy forest to the skies; Beneath, Charybdis holds her boisterous reign 'Midst roaring whirlpools, and absorbs the main; Thrice in her gulfs the boiling seas subside, Thrice in dire thunders she refunds the tide.