वे पदार्थ जिनसे होकर वस्तुओं को देखा जा सकता है, परन्तु स्पष्ट रूप से नहीं, क्या कहलाते हैं?

The arrival of which commission in India triggered widespread protests, including mass hartals across the country in 1928?

Which of the following leaders was instrumental in initiating and leading India’s struggle for independence?