正常成人血清白蛋白参考值( )。

A．46g/L～70g/L
B．60g/L～80g/L
C．35g/L～55g/L
D．28g/L～44g/L
E．20g/L～30g/L

Concerning the payment for the machines to be imported by us, we suggest that we make payment ______ three annual installments without interest.

A．by
B．with
C．for
D．on