八项质量管理原则中，( )是质量管理的关键。
A．关注焦点为顾客
B．全面质量管理
C．领导的作用
D．持续改进
参考答案：C
He is the lawyer who you took photos ____ you were in the Forbidden City.
A．when
B．of when
C．where
D．of where
怎样正确使用电动工具？
