单项选择题
A.4 B.8 C.16 D.64
A.1/16 B.3/16 C.2/16 D.9/16
A.无芒×无芒→F1无芒 B.有芒×有芒→F1有芒 C.无芒×无芒→F1无芒、有芒 D.无芒×有芒→F1无芒、有芒