F.3 phy,, about an unmarked thermometer.

the mark of unmarked thermometer is not zero cm when it is in melting ice ...
let the mark of unmarked thermometer is A cm(where A isn't equal to zero!)when it is in melting ice..and let the mark will be rise Bcm when it rise 1*c
so melting ice is A cm
10oC water is (A+10B) cm
40oC water is(A+40B)cm
A.4*1(2)+1(1)=4A+40B+A=5A+40B isn't equal to 1(3)
B.4*1(2)=4(A+10B)=4A+40B isn't equal to 1(3) again
C.4*1(2)-3*1(1)=4(A+10B)-3(A)=A+40B is equal to 1(3)
so there just c is correct

2008-06-11 21:48:48 補充：
當然唔係啦...話明係unmarked thermometer...冇話0度就0cm..
好似有d溫度計咁..個range係..-10度至120度...咁-10度個陣咪先0cm lo
又好似alcohol ge 溫度計咁..個range係攝氏-115至78度(好似係咁)
假設佢全長20cm...咁係攝氏0度時..佢就係115/193x20=11.917cm
而唔係0cm..
so唔同的溫度計係0度時..都唔同cm..
除非佢話明個range係0度開始啦~