将下列陈述句改成反问句
①那奔驰的列车正是我们祖国奋勇前进的象征。
②都是你自己找的，我帮不得了你的忙。
①那奔驰的列车不是我们祖国奋勇前进的象征吗？②都是你自己找的，我怎么帮得了你的忙？
He turned from side to side, eyeing himself in the mirror with a serious, studied ______ that soon changed into a smile.
