: difficult in a way that is usually interesting or enjoyable. Thesaurus: All synonyms and antonyms for challenging Nglish: Translation of challenging for Spanish speakers Britannica English: Translation of challenging for Arabic speakers.
To illustrate the tremendous indirect impact of emerging zoonotic diseases on public health policy and structures and on public perception of health risks, the authors provide a number of examples, including that of the Ebola virus, avian influenza, monkeypox and bovine spongiform encephalopathy.
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word zooplankton is derived from the Greek zoon, meaning animal, and planktos, meaning wanderer or drifter. Individual zooplankton are usually microscopic, but some are larger and visible with the naked eye.