---Let’s go hiking __________ staying at home, shall we? --- A good idea.

A．as well as

B．in order to

C．instead of

D．because of

进行总钙和离子钙测定时，不能采用的标本为( )

A．自然排出尿液
B．肝素抗凝血浆
C．血清
D．脑脊液
E．EDTA抗凝血浆