“Blanca fought the destruction and decline with the ferocity of a lioness, but it was clear that it was a losing.”

“He knew he will never see them again.”

“Having fed and care for them for so long.”

Do those look right to you? They don’t to me. There are obvious errors in each of these quotes. And while it’s not impossible that the author made the mistake and the editors didn’t catch it, it’s a lot more likely that the error is on the part of the student.

The problem with this is that we expect you to make mistakes in your own writing sometimes. But this isn’t your writing — this is just copying. And if your copying is that bad, it seems that you aren’t paying very much attention or taking the assignment very seriously. It looks lazy. At the very least, you should get your quotes exactly right. So double-check them before you finish. Look frequently from the book to the screen as you type. And then check them one last time. A mistake in your own writing is natural. A mistake in something you’re supposed to copy can destroy your credibility as a writer.

(P.S. In case you didn’t catch them, the first sentence is missing a noun at the end: proposition. The second one has verb tenses that don’t match (knew and will — will should be would). The third one is missing a “d” on the end of care — another verb tense issue.)