For this case, what we should do is fill in the blanks with the correct words.
The words we must translate are the words in parentheses.
1) The
2) Traveler
The words have different translation in Spanish depending on the gender.
The translation for the masculine gender in Spanish is:
The = El
Traveler = Viajero
Therefore, the complete sentence in Spanish is given by:
El viajero es el muchacho que viaja.
Answer:
El viajero es el muchacho que viaja.