产品生命周期包括
A．导入期
B．成长期
C．成熟期
D．衰退期
E．延伸期
参考答案：A,B,C,D
.Was it in 2000_________he was still in middle school_________this boy became an
expert at computer?
A．when; that
B．that; where
C．when; where
D．that; that
足厥阴肝经的起始穴是（）
A.隐白
B.涌泉
C.大敦
D.章门
E.期门
