Ans. to the ques. no-a 

We have acquired pieces of information about Garment washing, purpose, types of washing, impacts of washing, types, and capacity of chemical utilized in the washing plant. 

Ans. to the ques. no-b 

It would be better if we learn all of this by practice. 

Ans. to the ques. no-c 

Indeed, I have seen all the things that our respected sir had described previously.