Which of these human activities is most likely to cause an increase in the number of cases of heat exhaustion among humans? a. increased consumption of beef, which increases methane production b. use of solar panels instead of fossil fuels for energy production c. burning of plastics in open burn barrels d. use of hair spray containing chlorofluorocarbons

The appropriate answer is a. Increased consumption of beef which increases methane production. Increases in the number of cases of heat exhaustion will be caused by increases in temperature as a result of the exacerbation of the greenhouse effect which leads to global warming. Cattle production produces large quantities of methane as a result of the process of digestion in these animals. Methane, like carbon dioxide is a greenhouse gas however it traps more heat than carbon dioxide. Methane production as a result of livestock rearing will be the cause of the increased cases because it is practiced on a very large scale. Burning plastics and using cfcs do release greenhouse gases but on a much smaller scale. 
Using solar panels instead of fossil fuels will actually reduce the greenhouse gases if done on a large scale. 

For cyclohexane compounds drawn in a chair conformation:   -axial bonds are vertical  -equatorial bonds are parallel to two bonds within the ring.  thus, as i assume the chair conformation is drawn:   -the x group is in an axial position, as are the five other vertical bonds.  -three axial bonds are on the top face of the ring  -the other three axial bonds are on the bottom face  the position of the second substituent on each ring carbon is equatorial.  gauche groups must be on an adjacent carbon such as carbon 6 and carbon 2, and also gauche groups are rotated by 60 degrees relative to each other.  drawing the newman projections for c1–c2 and c1–c6 aids in visualizing the groups that are gauche to the y group on c1.  click this link and watch some academic videos that may you more understand the topic