A、The violin was too heavy for her. B、She was too young to play the violin. C、The violin was too expensive. D、Her mother wanted

When Midori was two years old, she often climbed onto the piano bench and reached for the violin that belonged to(19)her mother, a 38-year-old professional musician.
    "Please don’t touch, Midori," her mother scolded.(20)The violin was, after all, worth more than $20,000.
    But Midori insisted, and she longed to handle the graceful instrument that made beautiful sounds. Finally, on her third birthday, Midori was handed a package: a tiny violin, about half the normal size.
    Almost from the moment Midori was born, her mother knew she was sensitive to music. For several years mother and daughter practiced together day after day. She was eager to learn. Failure often led to tears, though she never once turned from the instrument. Instead, she persisted until the problem was overcome.
    One day Johnston, an American musician, heard Midori playing the violin. He couldn’t believe she was just eight years old.(21)"She must make a tape and I will take it to the United States," the musician said.
    A famous American violin teacher heard the tape. He, too, had difficulty in believing his ears. The playing was absolutely astonishing. He immediately accepted her as a pupil and recommended her for a full scholarship.(22)In 1982, Midori and her mother moved to New York City, leaving behind a comfortable life in Japan.
Questions 19 to 22 are based on the passage you have just heard.
19. What was Midori’s mother?
20. Why was Midori not admitted to touch her mother’s violin at the age of two?
21. What did Johnston, the American musician, ask Midori to do?
22. When did Midori move to the United States?