3891: The basic reason for the extraordinary sparkle of a suitably cut diamond is that
(a) it has a very high transparency
(b) it has a very high refractive index
(c) it is very hard
(d) it has well-defined cleavage planes
3892: The 'Fortaleza Declaration', recently in the news, is related to the affairs of
(a) ASEAN
(b) BRICS
(c) OECD
(d) WTO
3893: The major chemical compound found in human kidney stones is
(a) Uric acid
(b) Calcium carbonate
(c) Calcium oxalate
(d) Calcium sulphate
3894: The missing fraction in the series given below is :
4/9,9/90/........39/86
(a) 17/40
(b) 19/42
(c) 20/45
(d) 29/53
3895: River Luni drains into:
(a) Ganga delta
(b) Kerala coast
(c) Rann of Kutchh
(d) Godavari delta