~樂~

b..in fact its very easy

firstly 一定唔係c同d 因為設計者唔會想d水係架車入面boiling 而且係現實都係唔會
then a同b choose一

一定係b....因為e=mc (delta)t
c(即係specific heat capacity)大ge話呢 佢就可以吸得多熱 而水溫唔升得好高