血钙、血磷含量不是衡量钙、磷营养的必要指标，而骨骼中骨灰含量是衡量钙，磷的营养指标()。
参考答案：对
Being determined is a kind of quality and that’s ________ it takes to do anything properly.
A．how
B．which
C．where
D．what
