题干
When the children saw the snake, they all ran away in fear.
A：quickly
B：fast
C：with fright
答案(点此获取答案解析）
C
When the children saw the snake, they all ran away in fear.
A：quickly
B：fast
C：with fright
，某段时间内每部拖拉机的拉力对原木所做的功均为W。那么，在这段时间内，两部拖拉机对原木所做的总功为