As shown in the diagram, an empty cylindrical vessel of negligible thickness lies on a horizontal surface. The base radius of the vessel is
5 cm and the height is 20 cm. Inside the vessel is a wooden cube which
has side length 6 cm, and its weight is evenly distributed.
When floating in water, the top and bottom faces of the cube will be horizontal,
and 1313 of its volume is above water. How much water, in cm3cm3
, must be poured into the vessel so that the top face of the cube is level with the mouth of the vessel?（ 3.14 = π ）
Drying is the oldest type of food preservation. If water is (1) ________ from food, the bacteria can't grow. In (2) ________ times in hot countries, people simply left fruit and meat outside to dry in the sun and the wind until all its natural water was gone. This make the fruit last a very long time. Drying fruit sometimes results in a completely new (3) ________ . For example, grapes turn into raisins and plums turn into prunes. Drying food in the sun does not work in cooler or wetter climates, but people have other (4) ________ to preserve feed in cold places. 2. Salting: Salting food, especially meat and fish, is another very old way to preserve food. Bacteria cannot grow in a very salty environment, so salted food lasts a long time. In many countries, salt fish or meat has become a (5) ________ food and people still eat it today. For example, in Portugal the national dish is salt cod fish, and although people could buy fresh fish and (6) ________ it, they prefer to eat the preserved fish.
