只有有了清晰地目标，才有前行的方向和动力。()

A. 峻下冷积
B. 逐水退肿
C. 祛痰利咽
D. 破血消癥
E. 外用蚀疮

A. the early part of the 20th century
B. the middle part of the 20th century
C. the latter part of the 20th century
D. the early part of the 21 st century