[单选] If you can’t see anything， do you think you’ll have a nice future？ Xiong Linghao， a 19-year-old pianist， is giving us a great answer．The girl comes from Mianyang， Sichuan． She lost her eyesight （视力） not long after she was born． Luckily， music helps her． Thirteen years ago， she started to learn to play the piano． Different from other piano learners， she could only learn by “hearing” music in the beginning．问题 How old was Xiong Linghao when she began to learn to play the piano？