So one could have a very good day and test well, or one could just not be feeling one's best and test poorly.
所以，有些人可能因为这一天状态很好而取得好成绩，而有些人因为这一天状态不佳而发挥失常。
2
And evidence is cropping up to suggest that a poor night's sleep is not only felt the next day but could have implications for one's heart over the long term.