Question

ÔĶÁÏÂÃæ¶ÌÎÄ£¬È»ºó¸ù¾Ý¶ÌÎÄÄÚÈÝÑ¡Ôñ×î¼Ñ´ð°¸¡£ ¡¡¡¡Put an ice cube from your fridge into a glass of water£®You have a piece of string 10 centimetres long£®The problem is to take out that piece of ice with the help of the string£®But you must not touch the ice with your fingers£® ¡¡¡¡You may ask your friends to try to do that when you are having dinner together£®There is a saltcellar on the table£®You must use salt when you carry out this experiment£® ¡¡¡¡First you put the string across the piece of ice£®Then put some salt on the ice£®Salt makes ice melt£®The ice round the string will begin to melt£®But when it melts, it will lose heat£®The cold ice cube will make the salt water freeze again£® ¡¡¡¡After a minute or two you may raise your piece of ice! ¡¡¡¡This experiment can be very useful to you£®If, for example, there is ice near the door of your house, you must use much salt to melt all the ice£®If you don't put enough salt, the water will freeze again£® (1) We must use ________ when we carry out this experiment£® [¡¡¡¡] A£® a fridge B£® some food C£® a table D£® some salt (2) How long will it take to carry out this experiment? [¡¡¡¡] A£® More than three minutes£® B£® Five minutes or so£® C£® Only one or two minutes£® D£® About ten minutes£® (3) What is the purpose of this experiment? [¡¡¡¡] A£® Put the ice cube into the glass of water with the help of the string£® B£® Take out the ice cube in the glass of water with the help of the string£® C£® Take out the ice cube in the glass of water with your fingers£® D£® Put some salt on the ice cube and then put the string across it£® (4) How many things at least are used in this experiment? [¡¡¡¡] A£® Three£® B£® Four£® C£® Six£® D£® Seven£® (5) We can learn something about ________ from the passage£® [¡¡¡¡] A£® physics and biology B£® biology and science C£® chemistry and biology D£® physics and chemistry

Answer 1

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