1. Вставь Is или Are в начало вопроса: 1) ___ the green frog jumping? (образец); 2) ___ the polar bear swimming?; 3) ___ the monkeys climbing trees?; 4) ___ the brown donkey walking?; 5) ___ the spiders making a web?; 6) ___ the crocodile sleeping?; 7) ___ the two chickens running?; 8) ___ the pink jellyfish swimming?

1. Is the green frog jumping?
2. Is the polar bear swimming?
3. Are the monkeys climbing trees?
4. Is the brown donkey walking?
5. Are the spiders making a web?
6. Is the crocodile sleeping?
7. Are the two chickens running?
8. Is the pink jellyfish swimming?

Обоснование: is употребляется с существительным в единственном числе, а are — с существительным во множественном числе.