有些声音是人类耳朵无法检测到的。

Some sounds cannot be ___detected by the human ear.

这种特殊相机可以通过热量检测身体。

This special camera can ___detect bodies by their heat.

空气污染是一种相对容易检测到的污染类型。

Air pollution is a type of contamination that can be ___detected relatively easily.