abcgmat wrote:1. The questions in the sesssion were related to use of ING forms without comma's. The ING forms were either the first word of the sentence or were followed by a preposition(with ,to, by)

that's an unrelated topic.

the -ing forms in that study hall are all things that function grammatically as nouns; your examples here are modifiers. not the same thing.

2. Regarding Process Oriented.
Could you help me understanding how is this sentence process oriented
a. Swimming is a good excercise. (as we are not talking about process of swimming as in 'swimming involves moving legs and hands')

this distinction is only meaningful when the verb has an object, e.g., "burning fossil fuels" versus "the burning of fossil fuels". the former of these would be used to describe the process of burning fuels; the latter would be more appropriate in discussing larger concerns such as environmental effects.

for verbs that don't have objects, such as "swimming" in this example, there is no equivalent of the second form; you just use the gerund ("swimming").

--What is a question I should ask to know if the sentence is process oriented

at the risk of redundancy, the only way i know how to answer this question is "it's concerned with the process itself, rather than with some sort of larger consideration surrounding that process".

b. Majority of scientist believe that to reduce and stabilize Atmosperic concentration of carbon dioxide , emission must be cut at the source by burning fossil fuels more efficiently and, in some cases, by replacing fossil fuels altogether with alternatives such as hydigen fuel cells.

-- burning Fossil fuels and the replacing...are the steps to cut emission.
or emission cut involves burning Fossil fuels and the replacing..

[/quote]

first question -- where did you get the sentence up there?
it's definitely taken from some sort of formal source -- but you've inserted several miscellaneous errors typical of non-native speakers of english (e.g., "majority of scientist" instead of "the majority of scientists"). this is why i'm curious: it's clear that you didn't just copy and paste, or just transcribe, because you have effectively translated this sentence into your own version of english.
did you actually memorize this entire sentence in one piece? (if the answer is yes, that spells trouble.)

in this sentence, you don't have to be concerned with minutiae such as this difference, since there is a clear parallel structure issue.
if you have "burning x" and "replacing y", that's parallel.
if you have "burning x" and "the replacing of y", that's not parallel.
done.