Books are a worthy invention of human history since they make it possible for us to make a of human's thoughts.
A. plan
B. sign
C. point
D. record
网友回答
A. plan
B. sign
C. point
D. record
解析：名词辨析。A计划；B征兆；C点，意义；D记录。结合句意可知D正确。句意：书在人类历史上是一个非常有价值的发明，因为它让我们记录人类的想法变得可能。