题目

CO2供应不足最终可影响到绿色植物释放O2减少，下列叙述中最直接的原因是（）       A．  CO2不足使固定形成的三碳化合物减少       B．  三碳化合物还原所消耗的ATP和NADPH减少       C．  ATP和NADPH减少使光反应分解水减少       D．  ADP、Pi、NADP+减少使光反应分解水减少 答案：D阅读下面材料，在空白处填入适当的内容（不多于3个单词）或括号内单词的正确形式。Mr. Johnson lived in the woods with his wife and children. He owned __1. __farm，which looked almost abandoned.__ 2. __(lucky)，he also had a cow which produced milk every day. He sold or exchanged some of the milk in the towns nearby _3._other food and made cheese and butter for the family with what _4.__(leave)．The cow was their only means of support，in fact. One day，the cow was eating grass _5.__it began to rain heavily. While making great efforts to run away，she _6._(fall) over the hill and died. Then the Johnsons had to make a living _7.__the cow. In order to support his family，Mr. Johnson began to plant herbs and vegetables. Since the plants took a while to grow，he started cutting down trees __8.__(sell) the wood. Thinking about his children's clothes，he started growing cotton too. When harvest came around，he was already selling herbs，vegetables and cotton in the market __9._people from the towns met regularly. Now it occurred to _10.__that his farm had much potential and that the death of the cow was a bit of luck.