The mystery had now reached its climax: the man had undoubtedly been murdered, and it was

absolutely certain no one could conceivably have done it. It was therefore time to call in the great detective, who gave one searching glance at the corpse, then produced a microscope.

"Aha!" he exclaimed as he picked a hair off the lapel of the dead man's coat." The mystery is a mystery no longer. We have only to find the man who lost this hair, and the criminal will be in our hand." The inexorable chain of logic was complete, and the detective embarked on his search.

For four days and four nights he moved unobserved through the streets of New York, scanning closely every face he passed, looking for a man who had lost a hair. On the fifth day he discovered a man disguised as a tourist, his head enveloped in a cap reaching below his ears. The man was about to board the Gloritania, and the detective lost no time in following him on board.

"Arrest him!" shouted the detective, and then, drawing himself to his full height, he brandished aloft the hair." This is his," said the great detective," and it proves his guilt" .

"Remove his hat," ordered the ship's captain sternly.

It was discovered that the man was entirely bald.

"Aha!" exclaimed the great detective without a moment's hesitation." He has committed not one murder, but about one million!"

The detective declared the mystery solved before he ______.

A．found the hair

B．produced the microscope

C．searched for the murderer

D．glanced at the corpse