n.足跡
Then he went over the ground all round about, hiding every footmark. 然后，將四周每一個他自己的足跡抹掉。
The purpose analyses the correlativity between research footmark length and height and its change pattern in the round. 目的全面分析研究足跡長度與身高之間的相關(guān)關(guān)系及其變化規(guī)律。
