【答题库最新整理国开(电大)人文英语3-1379网上形考机考题库】The birth rate of the country decreases ______ with years.

【答题库最新整理国开(电大)人文英语3-1379网上形考机考题库】The birth rate of the country decreases ______ with years.
选择一项：
A. extremely
B. approximately
C. progressively
译文: 这个国家的出生率逐年递减。