Second, a failed test should indicate that something unexpected happened (for example, a reference is null) and normal execution can't continue.

其次，失败的测试应当代表发生了意料之外的事（例如，引用为空），正常的执行不能继续。

youdao

Normal control characters (characters with values less than 32) : This especially includes character 0, traditionally called NUL; I call it NIL to distinguish it from c's NULL pointer.

常规控制字符(字符值小于32)：还特别包括字符0，传统上称做NUL；我把它称为NIL以区别于c语言中的NULL指针。

youdao

Conclusion The activity of the histaminergic system decreased and the decrease might be one of the compensatory mechanisms for maintenance of the normal sleep in the null mice lacking DPR.

结论DPR基因敲除型小鼠脑中组胺能神经活性显著降低，这一变化可能是该种小鼠尚能维持正常睡眠的代偿机制之一。

youdao