Read the passage: \'Renewable energy sources like solar and wind now account for 30% of global electricity. However, their intermittency requires advanced battery storage systems to ensure consistent supply.\' What is the main challenge mentioned?

Choose the correct synonym of \'Voracious\':

The book is _____ the table.

Choose the correct sentence (mixed conditional):

Choose the correct synonym of \'Capricious\':

She insisted _____ seeing the manager.