nonnegative number

例句：

1. 1. The temperature is nonnegative at this time of the year.
   这个季节这个时候温度是非负的。
2. 2. The equation has a nonnegative solution.
   这个方程有一个非负解。
3. 3. The graph shows that the nonnegative numbers are increasing.
   这个图显示非负数是递增的。