Why do gold ornaments look new even after several years of use?

Why do Goldsmiths use a blow -pipe?

Veracular names given to the organisms in a particular language and region of the world. There are several types of names like English, Hindi, Gujrati, Marathi, Bengali, Tamil, etc. The names have been in use since times immemorial. New names are added whenever outside organisms are introduced into the area. Write two uses of vernacular names.

Veracular names given to the organisms in a particular language and region of the world. There are several types of names like English, Hindi, Gujrati, Marathi, Bengali, Tamil, etc. The names have been in use since times immemorial. New names are added whenever outside organisms are introduced into the area. Why veracular names can not be used by biologists? Give two reasons.

Write the physiological reason,why a woman generally cannot conceive a child after 50 years of age.

A man went door to door posing as a goldmith he promised to bring back the glitter of old and dull gold oranments an unsuspecting lady gave a set of gold bangles to him which he dipped in a particular solution the bangles sparkled like new but their weight was reduced drastically the lady was upset but after a futile argument the man beat a hasty retreat can you play the detective to find out the nature of the solution he had used?