The coefficient of friction can be set to any nonnegativevalue.
可以设置摩擦系数成任何非负值。
2
The resulting value must be a nonnegative integer less than the sequence's length, and the sequence is asked to assign the assigned object to its item with that index.
最后的值必须是一个小于该序列长度的非负整数，然后该序列就被请求将被赋对象赋值给它带那个指标的项。
3
An existence theorem of positive solution is established for a superlinear second-order three-point boundary value problem. Here, the nonlinear term is bounded below and need not be nonnegative.