base line

柯林斯词典

1. N-COUNT The baseline of a tennis, badminton, or basketball court is one of the lines at each end of the court that mark the limits of play. (网球场、羽毛球场或篮球场的)底线[usu sing]
Martinez, when she served, usually stayed on the baseline. 马第尼斯发球的时候，经常踩在底线上。
2. N-COUNT In baseball, the baseline is the line that a player must not cross when running between bases. (棒球场的)垒线[usu sing]
3. N-COUNT A baseline is a value or starting point on a scale with which other values can be compared. (价值的)基准[usu sing, oft N 'for' n/-ing]
You'll need such information to use as a baseline for measuring progress. 你需要利用这些信息作为基准来衡量进展情况。