Questions

Most of the emissions of greenhouse gases (GHG) come primarily from burning fossil fuels (coal, hydrocarbon gas liquids, natural gas, and petroleum) for energy use and the major greenhouse gas is of course carbon dioxide (CO2) which comes from burning fossil fuels and land-use change.

But methane (CH4) and nitrous oxide (N2O), which mostly come from agriculture and waste, are also significant GHGs and shouldn't be discounted.

Natural Gas is a Non Renewable Resource of Energy because that does not renew itself once used, unlike the other choices. 

It is a resource that will not be naturally replenished.

The condition in the while loop is a must.

Key Challenges of s/w testing:

1. Testing considered late in project

2. Requirements not testable

3. Integration is done after all components have been developed: This might result into full testing not being covered.

4. Complete testing is not possible

( int t ; t = a, a = b, b = t ;);

This code won't compile since declaration of t cannot occur within parentheses.