植物的光合作用受多种内、外因素的影响，在相同条件下，不同植物光合速率不同，这是由植物本身的遗传特性决定的，同一品种的光合速率主要受光照、CO₂浓度、温度、水分、矿质营养等环境因素的影响．甲图是在乙图 m 点的条件下测得的曲线，乙图是在甲图c点的条件下测得的曲线，请依图回答下列问题：

（1）限制甲图 C 点后光合作用速率增加的主要环境因素是____ ，限制m点的主要环境因素是____ ．b点时叶肉产生的O₂转移途径是____ 

（2）甲图两曲线的差异是由植物本身的____ 决定的．

（3）乙图中两曲线后段呈下降趋势的原因是____ ．

（4）如在乙图的 n 点条件下测得阳生植物光照强度与光合 CO₂同化速率关系曲线，则该曲线与甲图的阳生植物曲线比较 b、c 点的移动情况是____ 

（5）试提出农业生产中充分利用光能的一种措施：____ ．

在计算两位数加二位数或两位数减一位数时应注意：在计算过程中，数位一定要____。

完形填空

阅读下面短文，从下列各题所给的A、B、C三个选项中，选出可以填入空白处的最佳答案。

My mother’s loving hands

      Night after night, she came to help me sleep, even long after my childhood years.

      I don't remember1it first started making me a little angry 一 my mom's hands pushing my hair that way. But it really made me uncomfortable, for they2rough（粗糙的）against my young skin. Finally, one night, I 3 her, "Don't do that any more. Your hands are too rough!" She didn't say anything,4 she never did it again.

      Years later I missed my mother's5and her goodnight kiss on my face. I'm not a little girl any more. My mom is6 her mid-seventies, and her rough hands are still doing things for my family and me.

      Now my own children have7. It was late on Thanksgiving Eve. As I slept in my bedroom, a familiar hand ran across my8to push the hair from my head. Then a kiss, ever so softly, touched my brow（额头).

      Taking my mom's hand, I told her how9 I was for that night I shouted at her. But my mom didn't know what I was talking about. She had forgotten it long ago.

      That night, I10with a new appreciation（感激）for my mother's caring hands. And the guilt（内疚）that I had carried around for so long was nowhere to be found.

心脏四个腔中，心脏壁最厚的腔以及与之相连的血管分别是（    ）

某同学的听课笔记中记载了以下信息：“历时十个月，双方伤亡七十万人，有‘绞肉机’之称。”据此我们可以判断，该同学学习的内容是（    ）