听力原文：Penury was what people called a mystery man. We had known him for over seven year

听力原文： Penury was what people called a mystery man. We had known him for over seven years, ever since he became a member of our modest club, but he had a way of keeping his private life to himself in all but the unessential details. We knew his address, though he never invited us to his home, and his age, too, but only unimportant matters of this kind. It seemed that he did not have to work for a living as we did, in our various ways. He had once hinted about an inheritance on which he managed to live comfortably. He was not, however, a man of luxurious habits: he was not especially well dressed and he did not even have a car. At the age of forty-five he was still a bachelor though. Since marriage was not a subject he ever discussed, we had no means of finding out whether he regretted not having a wife.

Penury disappeared suddenly from our circle and shortly afterwards we came to learn the first really solid facts about our mystery man. From reports that appeared in the newspapers, together with photographs of the man who was without doubt, our Mr. Penury, it was revealed that he was the most accomplished burglar in the London area; and that he had practiced this profession for many years, until he was arrested and sent to prison.

(23)

A．Because nobody knew his address.

B．Because nobody knew his age.

C．Because Penury's private life was a secret.

D．Because Penury was still a bachelor at the age of forty-five.