We all know that a magician does not really depend on "magic" to perform. his trick.【C1】__

____ on his ability to act at great speed.【C2】______ , this does not prevent us from enjoying watching a magician【C3】______ rabbits from a hat.【C4】______ the greatest magician of all time was Harry Houdini who died in 1926. Houdini mastered the art of【C5】______ . He could free himself from the tightest knots or the most complicated locks in seconds.【C6】______ no one really knows【C7】______ he did this, there is no doubt【C8】______ he had made a close study of every type of lock ever【C9】______ . He liked to carry a small steel needle-like tool strapped to his leg and he used this in【C10】______ of a key. Houdini once asked the Chicago police to lock him in prison. They【C11】______ him in chains and locked him up, but he freed himself【C12】______ an instant. The police【C13】______ him of having used a tool and locked him up again. This time he wore no clothes and there were chains around his neck, waist, wrists, and legs; but he again escaped in a few minutes. Houdini had probably hidden his "needle" in a waxlike【C14】______ and dropped it on the floor in the passage.【C15】______ he went past, he stepped on it so that it stuck to the bottom of his foot. His most famous escape, however, was【C16】______ astonishing. He was heavily chained【C17】______ and enclosed in an empty wooden chest, the lid of【C18】______ was nailed down. The【C19】______ was dropped into the sea in New York harbor. In one minute Houdini had swum to the surface. When the chest was【C20】______ . it was opened and the chains was found inside.

【C1】

A．but

B．then

C．and

D．however