A:to have;you to be
B:having;that you being
C:to have;you are
D:having;that you are
____,五十弦翻塞外声。 (辛弃疾《破阵子•为陈同甫赋壮语以寄》)
某生物兴趣小组用显微镜观察人体口腔上皮细胞,下列哪一个结构是这些细胞没有的( )