Translate the given Spanish text to English

[EX Q]: The second arm portion is pivotably connected to the walls.
[EX A]: La segunda porción del brazo se conecta en pivote a las paredes.

[EX Q]: Other methods and systems are included.
[EX A]: Se incluyen otros métodos y sistemas.

[EX Q]: Neither of these radicals has any benzyl hydrogen atoms.
[EX A]:
Ninguno de estos radicales tiene ningun atomo de hidrogeno del bencilo.