在进行植物分类时,小刚将玉米、向日葵、油松归为一类,将肾蕨、葫芦藓、水绵归为另一类,他的分类依据是( )
A:是否有根
B:是否有茎和叶
C:能否产生种子
D:能否形成果实
下列实验操作中正确的是( )
—When Mum is at home, I have to practice every day, but she is on a business trip this week.