Step-by-step reasoning process: Plants produce oxygen which is needed by humans to survive. Quartz is a hard mineral substance made of several elements. Quartz is composed of silicon and oxygen. Quartz can be melted at high temperatures.
[Q and A]: Could Quartz be useful to humans if plants died off and there was no oxygen?
yes

Step-by-step reasoning process: Martin Luther published a list of 95 theses as his critique of the church. There are approximately 182 days in 6 months.
[Q and A]: If Martin Luther did one theses a day would he run out in half a year?
yes

Step-by-step reasoning process: Sea otters prey mostly on marine invertebrates and other aquatic creatures. Spiders are not aquatic creatures and they reside on land.
[Q and A]:
Does a sea otter eat spiders?
no