The "one" could imply that of the alternates only ONE choice is possible, or permitted. "Which" alone could indicate several choices from the set of alterates could be selected in various combinations. Of course, speakers are often very imprecise about their meanings & intentions when saying "which" or "which one". Usually the context makes it clear if the choices are mutually exclusive or not ...
One-to-one is used when you talk about transfer or communications. You may use one-to-one when you can identify a source and a destination. For eg., a one-to-one email is one sent from a single person to another, i.e., no ccs or bccs. In maths, a one-to-one mapping maps one element of a set to a unique element in a target set. One-on-one is the correct adjective in your example. See Free ...
Which one is grammatically correct or better? I have two assignments, One of them is done. I have two assignments, One of which is done. I watched a video tutorial that the teacher said the ...
Is it correct to say your pronouns are "she/they" or should it be "she ...
The difference is that she's and similar shortened forms are used in colloquial speech, but not in certain cases. In your example, she is being emphasised.
Taken from the Free Online Dictionary: Usage Note: Using she as a generic or gender-neutral singular pronoun is more common than might be expected, given the continuing debate regarding the parallel use of he. In a 1989 article from the Los Angeles Times, for instance, writer Dan Sullivan notes, "What's wrong with reinventing the wheel?