Mr Smith _____the grammar book meant for senior high school students and will almost finish it.[ ]

A. was writing  

B. has written  

C. has been written  

D. has been writing

隐蔽性通货膨胀发生时，物价总体水平（　　）。

A．明显上涨

B．变化不明显

C．明显下降

D．持续下降