Between 4.5 and 3.8 billion years ago, the earth became so that it was not clear whether the shape would last or not.
A. genuine
B. slight
C. solid
D. violent
网友回答
A. genuine
B. slight
C. solid
(答案→)D. violent
解析：考查词义辨析，genuine真心的，slight轻轻的，solid 坚固的，violent猛烈地，句意：在4.5到3.8亿年前，地球变得如此的猛烈以至于不清楚形状是否会不会持久。故选D。