The lady _________ dancing as a hobby in her sixties, and she is really good at it now.

A．dressed up

B．looked up

C．took up

D．put up

主要用于制造高强度和耐蚀的容器、结构和零件的不锈耐酸钢是（）不锈钢。

A．铁素体型

B．马氏体型

C．奥氏体型

D．沉淀硬化型