be flat

• 淡而无味

be flat的用法和样例：

例句

1. After running in the marathon, she was flat out for a week.
   她参加马拉松比赛后一星期都疲惫不堪。
2. People used to think that the world was flat; now we know it is round.
   从前人们以为地球是平的，现在知道是圆的。
3. The land was flat and treeless and gave no cover to the troops.
   该处地势平坦又没有树木，部队无处隐蔽。
4. The market has been flat today.
   今天市场上生意一直很清淡。