The answer is A.number of protons in the nucleus.
Answer:
The internet is most useful to them because they use it to communicate.
Explanation:
If I were to send a message to my brother in Florida, through the internet, while I'm in Pennsylvania he would get it in minutes. On the other hand if I were going to meet him and then explain what I wanted to tell him in person it would take a much longer time.
Answer: Yeast produces carbon dioxide
Explanation: Yeasts feed on the sugars in flour and releases the carbon dioxide that makes bread rise.