On a night when the sky is clear, the temperature may dip considerably; on a cloudy night the temperature will usually dip much less. The reason for this difference is that
Options: the clear sky allows radiant energy to escape readily from the earth, on a cloudy night the clouds are warm and therefore retard the cooling, the clear sky allows the cold of outer space to reach the earth, current of air carry the heat away from the earth on a clear night
Options: a club or a local sport association for remarkable achievements, amateur athlete, not necessarily an Olympian, National Olympic Committee for outstanding work, None of the above
It is more difficult to walk on a sandy road than on a concrete road because
Options: sand is soft and concreter is hard, the friction between sand and feet is less than that between concrete and feet, the friction between sand and feet is more than that between concrete and feet, the sand is grainy but concrete is smooth
Which of the following international organisations has started the scheme 'Partnership for Peace' for a group of nations?
Options: Organisation of Petroleum Exporting Countries (OPEC), Economic and Social Commission for Asia and Pacific (ESCAP), North Atlantic Treaty Organisation (NATO), Organisations of African Unity (OAU)
Options: make the taste of food better, produce in small amounts the hydrochloric acid required for the digestion of food, ease the process of cooking, increase the solubility of food particles in water