day and night line

基本解释

The second line of the verse says that we should wait on our sick parents day and night, without leaving their bedside.
所以这后两句文字，说不论白天夜晚都侍奉着，不离开父母的床边；
The shape of this line between night and day varies with the seasons, which means different lengths of days and differing amounts of warming sunshine.
这条黑夜与白天分界线的形状随着季节的变化面变化，它代表着不同的白天时间长度和不同的阳光照射量。
But after 45 minutes of daylight, a dark line appears on the planet, dividing Earth into night and day.
但在 45 分钟的日光照射之后，一道黑暗线就出现在地球上了，它将地球分割为白天和黑夜两个地区。