This experiment was harmless to the animals.
这个实验对动物无害。
Not all chemicals normally present in living organisms are harmless.
并非所有正常存在于活的有机体中的化学物质都是无害的。
The mountain hasn't been entirely harmless, however.
然而，这座山并非完全无害。
On their own, cookies are generally harmless, if mildly intrusive.
就其本身而言，信息包通常是无害的，即使有轻微的干扰。