题目

  It was two years ago in winter when I went with my family to Engadine in Switzerland. The journey by car was pleasant until we reached the bottom of the Julier Pass(尤里尔隘口) when it began to snow.   Suddenly, the weather became very bad and soon we found ourselves in a storm. On the top of the pass, the visibility(能见度) was almost zero and we had to guess where the crash barrier(防撞护栏) was. It was terrible, the snow turned into ice and stuck to the windows despite the heating being set at full blast. Several times I had to get out of the car to clear the ice from the wi（11分）为研究CO2浓度和矿质元素含量对植物光合作用的影响，有人用同一环境中生长的两种植物，在适宜条件下做了模拟试验，结果如下表，请据此回答问题。项   目物种355μmol·mol-1的CO2539μmol·mol-1的CO2不施磷肥施磷肥20 kg·hm-2·a-1不施磷肥施磷肥20 kg·hm-2·a-1光合速率μmol·m-2·s-1欧州蕨2.183.743.625.81石楠1.376.765.4315.62（1）题干中的适宜“条件”是指         （至少两个）等。（2）根据实验结果，施磷肥对         的光合作用影响更大。磷被植物吸收后可用于合成         （至少两种）物质，以促进光合作用。（3）中耕松土能促进根细胞的         ，从而促进离子吸收。能否吸收某种无机盐离子以及吸收的多少，取决于根细胞膜上                  。（4）CO2浓度主要影响光合作用的         反应，如果将CO2浓度从355μmol·mol-1迅速提高到539μmol·mol-1，植物细胞叶绿体中C5的浓度将         。（5）下图表示欧州蕨在夏季晴朗的某一天CO2吸收量的变化曲线。该植物进行光合作用的时间区段是          。在C时刻光合作用的速率是         mg/dm2.h CO2。（6）据图推测，在时间C-D段与E-H段曲线下降可能的原因，前者是                ；后者是             。