A:Cd(OH)2
B:Ni(OH)2
C:Cd
D:NiO(OH)
—How long have you _________ your watch? It looks new.
—Only about three weeks.
①细胞壁 ②细胞膜 ③细胞质 ④细胞核 ⑤叶绿体 ⑥液泡 ⑦线粒体.