Answer:
B. carbon dioxide for oxygen
The best summary of the process of natural selection will be provided bythe option D that is genes are always passed from parent to offspring .
The natural selections has four constituents:
1) Varations
2) Inheritance
3) High rate of population growth
4) Survival and reproduction
Hence , out four inheritance is one of the option in the given question that is gene are passed from parent to offspring .
Answer:
Cilia that line our respiratory system help trap dust and other foreign particles, thereby preventing them from further entering our body and causing problems.