They are always harmful but never beneficial or neutral.

Are you referring to symbiotic relationships between organism? If so, the answer would be parasitism.

One organism, a parasite, takes advantage of another organism at the expense of the host organism.

Ex. A tick bites a dog for blood to use as food. The dog gets an uncomfortable bug bite and the dog might catch a tick borne disease.

parasitism

Explanation:

parasitism is a symbiotic relationship between 2 organisms, where one organism (the parasite), lives on/in another organism (the host), causing it some harm.

lizards have adapted to life in the desert. some desert lizards have toes with spiny scales to them run across the sand without sinking. some use the sand to hide from predators, or to search for small animals that they prey upon.

the answer is admiramos

the rule for verbs is whoever you are referring to (in this case 'nosotros'), you need to change the ending of the word.

nosotros - amos

yo - o

tu - as

el, ella, usted - a

ellos, ellas, ustedes - an

(examples: nosotros bailamos (instead of bailar) or yo hablo (instead of habla)