GENERAL SCIENCE PDF for RAILWAY EXAM GROUP D 2018 || GENERAL SCIENCE for RAILWAY EXAM 2018

GENERAL SCIENCE PDF for RAILWAY EXAM GROUP D 2018 || GENERAL SCIENCE for RAILWAY EXAM 2018 1.Piano was invented by ________. पियानो का _______आविष्कार द्वारा किया गया था (a) John Barber/ जॉन बार्बर (b) Sir Henry Cole /सर हेनरी कोल (c) Josephine Cochrane/ जोसफिने कोचरन (d) Bartolomeo Cristofori/ बार्टोलोमेओ क्रिस्टोफोरी    2.What is the viscosity […]