[71] objetos de cemento armado, objects of reinforced concrete. The article is omitted before a noun modified by an adjectival phrase. This also applies to azulejos, mosaicos, etc., in 67.
[72] puertas-cancelas, and not puerta-cancelas. Note that this compound word is made of two nouns and that it is used only in Latin America. Also cancel, puerta cancel.
[73] Se emplea and not se emplean.
[74] Uno y otro sistema, Both systems. VARIANTS: Ambos sistemas; los dos sistemas.
[75] Como iba diciendo, As I was saying. VARIANT: Como decía (not dije).
[76] toma-corrientes. See 72.
[77] de las, of those. VARIANT: De ésas.
[78] de las denominadas, of those called. VARIANT: De las que se denominan (or llaman). Note that past participles used as adjectives are inflected like adjectives.
[79] Por su parte, el cerrajero, The locksmith, in turn. VARIANTS: En cuanto al cerrajero; por lo que toca (or concierne) al cerrajero.
[80] al cuidado de. VARIANT: A cargo de.