读图，完成下列问题。地震波在经过B界面时传播速度有什么变化？

     Diana Velez does everything with maximum effort  and at maximum speed. That__1__
learning a new language, completing two certificates and opening a store.
     When arriving in Canada in 2008, she had one__2__: to have what she had back home
in Colombia. "I didn't want to__3__what I do, like so many who come to a new country,"

 she said. "I__4__to open a store here in Canada but knew I had to__5__myself properly."
     Diana quickly realized that making her dream of shop ownership in Canada a__6__meant
going to school to get the__7__education and certification. "My experience of owning a shop
and working as a designer in Colombia gave me__8__in my abilities, but I couldn't speak the
language and I had to__9__how to do things in Canada. It was like having to__10__all over
again," said Diana.
     __11__, she found just the help she needed for her relaunch (重新开张)__12__continuing
education at George Brown College. She began taking__13__for both the Essential Skills in
Fashion Certificate and the Image Consulting Certificate in May 2009.__14__Diana met with
the language barrier, she was always going__15__while at college.
     By the end of October 2009, she had completed all certificate requirements. Within two
years after her__16__in Canada, Diana at last achieved her__17__goal when her new store
opened its doors in Toronto's Sheppard Centre. She was on the fasttrack to__18__.
     Looking back, Diana, a fashion(时装)designer,__19__her achievements to the goal she
set, the education she received from the college, and__20__, the efforts she made. Now
Diana is very happy doing what she is doing.