Why does everything need to match in gender and number?

Because in the spanish language it's necessary to be able to reference back to what you're talking about. So when you're saying Es rojas, the listener knows that you're talking about multiple if a feminine object

Ithink it is d but dont beleive i really dont you to get it wrong.
why dont you use a translator. just download the google translate app that allows you to gake a photo and then it translates everything for you.
well i hope that works and good

Muchas playasanswer: muchas playas'the area's surf beaches include playa santa teresa and playa mal país in the south, and playa grande, in las baulas national marine park, in the north. leatherback turtles nest and hatch at playa grande.'