The sentence in question is: "She has been working here ___ five years." To fill in the blank correctly, we need to choose the appropriate preposition. The options provided are "since," "for," "from," and "during."
Let's evaluate each option:
In the context of the sentence, we are referring to the total duration of time over which she has been working. Therefore, the correct option to fill in the blank is "for," making the complete sentence:
"She has been working here for five years."
The manager asked the team to complete the project _______ the end of the week.