Question

scienc find this fast​

Answer 1

Answer:

Here is your answer...

Explanation:

1 => The roof of a movie theatre and a conference hall is curved so that the sound after reflection from the ceiling reaches all the parts of the hall uniformly. ... Thus, the sound goes through multiple reflections from the rigid walls of a closed and empty room without the reflections of the sound being absorbed.

2 => Biogas is an eco-friendly fuel because it helps to reduce the greenhouse gas emissions and our dependency on fossil fuels. It is produced from decomposition of organic matter, thus is an effective way of disposal of organic waste.

3 => When washing soda (Na2CO3. 10H2O) is added to the hard water, Na2CO3 reacts with the chlorides and sulphates of calcium and magnesium and converts them to insoluble carbonate salts. This changes the hard water into soft water and thus makes it suitable for use.

Mark me as brainliest

Answer 2

Answer:

here is yr answer

Explanation:

the roof on top of the house