Answer: They are sterile
Explanation:
Mule is a hybrid of male donkey and female horse with different chromosome number and is considered superior to both horse and donkey. Still it is considered as a weak hybrid this is because the mule is sterile which means that it cannot reproduce further.
The mule though is superior in many ways such as it can jump and is strong. The hybrid of mule is not good as it cannot continue its next generations on earth.
They are sterile and so is a weak hybrid.
Oxygen cycle The cycling of oxygen between the biotic and abiotic components of the environment (see biogeochemical cycle). ... In the process of respiration oxygen is taken in by living organisms and released into the atmosphere, combined with carbon, in the form of carbon dioxide.
Venus is the answer, you can tell easily because Venus has no moons or rings :)
The coexistence of eight species of woodpeckers in Oregon forests is an example of
Resource partitioning