1. A: Are either of the twins good swimmers? (be)

B: Yes, both of them are excellent swimmers, (be)

2. A: Which newspaper would you like to read?

B: The Times or the Guardian. Either is fine, thanks.(be)

3. A: Does every child get a prize? (get)

B: No, but each child who takes part gets a small gift. (get)

4. A: Who is each person in the team responsible to? (be)

B: Everyone reports to the Sales Manager. (report)

5. A: Where is all the money I gave you? (be)

B: Half of it is still in my bank account. (be)  

6. A: Are all of the things I asked you to get in the kitchen? (be)

B: Yes. I put them away for you.

Explicação:

No present simple o verbo "to be" possui três formas: am / is / are - variando conforme o sujeito da frase em questão. No geral, vale lembrar que "is" é singular e "are" é plural :)

I am

You are

He/ She is

We / They are

Já os outros verbos como "report" e "get" recebem a letra S quando são terceira pessoal do singular (he she) e também em "either" (qualquer), "who" (quem) e "everyone" (todo mundo).

Espero ter ajudado!