根据下列内容，回答191-195题。
Mrs．Janes gave music lessons at a school．She had a good voice and enjoyed singing，except that some of her high tones sounded like a gate that had been forgotten to oil．Mrs．Janes knew her weakness well，and took every chance she could to practice these high tones．As she lived in a small house，where she could not practice without disturbing the rest of the family，she usually went for long walks along the country roads whenever she had time and practiced her high tones there．Whenever she heard a car or a person coming along the road，she stopped and waited until she could no longer be heard before she started practicing again，because she was a shy person．
One afternoon，a fast，opened car came up behind her so silently and so fast that she didn’t hear it until it was only a few yards from her．She was singing some of her highest and most difficult tones at that time and as the car passed；she saw an anxious expression came over the driver’s face．
He stopped his car suddenly，jumped out and began to examine all the tyres carefully． Mrs．Janes didn’t dare to tell him what noise he had heard really was，so he got back into the car and drove off．
How did Mrs．Janes sing? __________

A.She sang well，but she didn’t practice singing hard．
B.She enjoyed singin9，but she had a terrible voice．
C.She was a good singer，but she could not sing the high tones well．
D.She sang terribly，and she was not singer at all．