It depends what kind of activist we are talking about. If the activist was for human rights, we could possibly consider them as a humanitarian, because the definition for humanitarian is: concerned with or seeking to promote human welfare. This is quite similar to a human rights activist, so I would say yes.
Answer:
(of a person or their efforts) persisting tirelessly.
Explanation:
Ultima came to stay with the Márez family,
And was encountered by a plea.
Uncle Lucas was cursed by the witches,
And Ultima came to put up the stitches.
Tenorio accused her of witchcraft for his daughter's demise,
But Ultima never fell for such chastise.
Antonio dealt with much concern and inquisition,
And Ultima was there to offer elucidation.
The Telléz family was befell by malediction ,
And Ultima brought their affliction to sedation.
Ultima was a benefactor all the way,
Until her owl was shot on the last day.
Answer:
I imagine that the Zebra mussels are not predators of the Unionod Mussel, so it must have something to do with a struggle for resources. If the population of Zebra Mussels increase, the Zebra mussels will use up and essentially hoard resources like food and the Unionod mussels will no longer have access to what they need to survive. I hope that this helps a little bit!
