The nurse is providing breast cancer education at a community facility. The American Cancer Society recommends that women get mammograms

A. yearly after age 40.
B. after the birth of the first child and every 2 years thereafter.
C. after the first menstrual period and annually thereafter.
D. every 3 years between ages 20 and 40 and annually thereafter.

发酵技术已经从利用自然界中             的微生物进行发酵生产的阶段，进入到按照            创造出具有            的微生物，以生产                        的发酵产品的新阶段。