Questions

If some action has started in the past and is still continuing, then present perfect continuous tense should be used instead of present continuous tense. So, the phrase ‘am waiting’ needs to be replaced with ‘have been waiting’ to make the sentence contextually correct. Thus, the correct formation would be, ‘I have been waiting for three –quarters of an hour’.

Narmada is the only river which flows from south to north in the given options.

Ashtadhyayi was written by Panini. He was a Sanskrit grammarian who gave a comprehensive and scientific theory of phonetics, phonology, and morphology. Panini was born in Shalatula, a town near to Attock on the Indus river in present day Pakistan.

The 3 states are Andhra Pradesh, Karnataka and Odisha.

A compiler is not a software.

Adobe, Microsoft office and Drivers are all software on a computer.

Geothermal energy is heat energy generated and stored in the Earth. Geothermal energy has been used for thousands of years in some countries for cooking and heating. It is simply power derived from the Earth's internal heat.