an, _____ private car is ______popular means of transportation

Mary is a humorous and warm-hearted woman and that isshe is a most popular person in her community

My mother is always warning me when I go out, “Don’t get off the bus ________ it is stopping.”[ ]

She is stubborn in resisting his enquiries about the Moonstone _____ the degree that she makes it seem as if she does not want the mystery ______

Is this the reason _______ at the meeting for his carelessness in his work?