It was reported that the government official expressed the deepest ______ to the families of those killed and injured in this attack.

A．satisfaction

B．substitute

C．symptom

D．sympathy

常听人们说“红花尚需绿叶衬”．人们见到的植物叶子之所以显绿色的，是因为绿色的叶子能______（选填“吸收”或“反射”）绿光．但如果是晚上用红色灯光照绿叶，人们见到的绿叶的颜色将是______色．