根据短文内容，选择正确答案。

     Feeling sad? Go shopping, because it really can make you happy again.

Scientists interviewed hundreds of shoppers at shopping centers, and they asked them to keep diaries of their shopping trips. The people who were unhappy on their way into a shop, they all became happy after the shopping. This is called “retail therapy”.

     Shopping is good for your health. Walking between shops and carrying heavy shopping bags burns 385 calories(卡路里) a week for a British woman, according to a study. The study tested 10 shoppers—five men and five women. It found that women cover an average of nearly three miles during the 2.5 hours they spend walking in me shopping centers every week. But men spend just 50 minutes shopping and cover just 1.5 miles.

农民在储存玉米种子前，需将刚收获的玉米种子晒干后，才收进粮仓存放．如果暴晒的时间不够长，在粮仓中堆存时玉米会产热以致霉烂．根据科学研究，玉米的产热量与种子消耗氧气量成正比．播种玉米时，农民将玉米种子放在水中浸泡一段时间，随着浸泡时间的延长，种子产热速率也越来越快，种子逐渐变“甜”，几天后，种子开始发芽，这时玉米种子内的含水量达到峰值．请根据以上事实及所学知识回答下面的问题．

（1）农民晒玉米种子时种子失去的主要是以____的形式存在于细胞中的水．当把种子晒干后加热烘烤，直至碳化，此时失去的水分主要是____ 

（2）随着浸泡时间的延长，玉米种子变甜，这种甜味物质是____，可用____试剂进行鉴定，它是由种子中的____ （物质）进行水解生成的．

（3）通过上述事实可以看出，细胞的代谢强弱与细胞的____有密切联系．