A tiger marks the boundaries of its territories by spraying urine and other bodily liquids on bushes. But it tries to avoid territorial fights, being guided by the distinctive body smell of other tigers.请问红字部分怎么理解?
...east once in their lives, but those who are sleep deprived are more likely to have panicked episodes of sleep paralysis that are usually accompanied by hallucinations, as well. 老师,请问as well前面为什么要加逗号,可以省略逗号吗?谢谢