— I didn't know it _________ Mary told me about it.
A:until
B:when
C:as soon as
物理知识在生产和生活中有着广泛的应用:如三峡船闸是利用 ____ 的原理;书包带做得宽宽的,是为了减少 ____ ;拦河大坝设计成下宽上窄形状的依据是根据 ____ 规律.