Convert the following direct speech to indirect speech:
"I can't express in words how much excitement I feel about the next chapter of our expedition," exclaimed Robert to his fellow adventurers.
1
Robert exclaimed to his fellow adventurers that he cannot express in words how much excitement he feels about the next chapter of their expedition.
2
Robert declared to his fellow adventurers with excitement that he couldn't put into words the level of exhilaration he felt about the next chapter of their expedition.
3
To his fellow adventurers, Robert spoke excitedly, expressing his inability to put into words the level of thrill he felt regarding the next chapter of their adventure.
4
Robert expressed to his fellow adventurers, in an excited tone, his inability to construct his thrill for their expedition's next chapter into words.