A:to be caught; to break away
B:being caught; breaking away
C:to be caught; broke away
D:being caught; broke away
①肉类 ②奶和奶制品 ③谷类 ④脂肪 ⑤蔬菜和水果类.
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生物学家利用人体干细胞培养出了人的心肌细胞,这种技术最关键的步骤是诱导干细胞( )
下列说法正确的是( )