If the thought of a nice, hot, fresh bread roll makes your mouth water, then your body will produce saliva, which contains the enzyme, amylase, to begin to digest it.

• 如果想到一个香喷喷、热腾腾的新鲜面包卷而使你流口水，此时你的身体正在分泌唾液，其中就有酶，特别是淀粉酶，开始来消化这块面包卷。