J is higher than temperature than K(1m). It's because impurities can change the flavor, smell and boiling point(1m).J hasn't any impurities.(1m) Hence J is easier to boil and higher temperature than K.
刚好我也是初二，而且嗯科学成绩勉强还好，我为你做解释一下是指Point一分.因此如果这道题是三分的话，我觉得是可以拿满三分，当然呃要看你的老师是怎么改的。