The periodic rise and fall of the sea level on the earth, gives rise to tides. This is related to
Options: the position of the moon with reference to the earth and the gravitational pull exerted mainly by the moon and partly by the sun, infrared rays from the sun, ultraviolet rays from the sun, None of the above
Options: slowing down of economic activity over a limited period, period during which unemployment may rise and demand and output may fall, leading to slump in trade, period that results from accumulation of unsold goods, owing to fall in demand, All of the above
When did the USSR formally disintegrates into 15 republics?