Questions

Silence is what is so delicate that even mentioning it breaks it.

It's a logic question. The answer can be

Boy can propose because he is not blind,deaf n dumb. It was not mentioned that the girl have to understand his proposal.

Silver nitrate is the basic substance from which silver bromide is obtained. The photographic films are impregnated with the light sensitive AgBr.

Monoculture is a typical characteristics of Commercial grain farming.

Monoculture is the agricultural practice of producing or growing a single crop, plant, or livestock species, variety, or breed in a field or farming system at a time focussing commercial gains.

Monoculture is widely used in both industrial farming and organic farming and has allowed increased efficiency in planting and harvest.

Polyculture, where more than one crop is grown in the same space at the same time, is the alternative to monoculture.

A Dome-shaped, muscular and membranous structure that separates as a partition of the thoracic and abdominal cavities is Diaphragm. 

Thoracic or chest cavity ::  It is the cavity where the heart and lungs are present. It is the second largest hallow space in the body.It also has vertebral column, ribs, breast bone,...

Abdominal cavity :: It is the cavity where the digestive tract, liver, kidneys, the spleen, pancreas,... are located. It is the largest hallow space of the body.