电源《阿凡达》中的发光植物为我们打造了一幅绚丽、梦幻的外星世界景观．现在，这种会自发光的植物已经被科学家带到了现实生活中．据报道，美国科学家近来利用生物技术成功培育出了名为“星光阿凡达”的发光烟草，它甚至可以代替灯泡来照明．

（1）科学家将海洋发光细菌的DNA片段引入烟草中，对野草进行了基因改良，使其能够自然、主动、持续的发光，这种技术称为____ ．

（2）自发光是烟草通过生物技术获得的性状，说明生物性状受____ 控制．

（3）烟草花色的红色和黄色是一对相对性状．红花烟草和黄花烟草杂交，后代全部是红花烟草（如图）由此判断____ 是显性性状．

（4）烟草花叶病毒能够引起烟草叶出现黄绿相间的病斑，即烟草花叶病．该病毒结构简单，仅由蛋白质外壳和RNA（核糖核酸）组成．以下是烟草花叶病毒浸染烟叶的实验：

烟草花叶病毒烟叶烟叶出现病斑烟草花叶病毒

烟草花叶病毒的蛋白质外壳烟叶正常烟叶无烟草花叶病毒

烟草花叶病毒的RNA烟叶烟叶出现病斑烟草花叶病毒

以上实验结果说明：烟草花叶病毒的遗传物质是　____ ．

（5）如果烟草花叶病毒浸染“星光阿凡达”发光烟草．理论上发光烟草是否会感染烟草花叶病？____ 

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。

    What was supposed to be ____ fun climb became a test of friendship for two young people from Canada last Saturday. Jeremy Savage and Ian Marshall, both aged 17, went ____ ____no problems.

    However, trouble began when they started the climb down the mountain. On one very ____ (danger) part of the path, Ian fell three meters off the side of the path. Jeremy was able to climb down to where Ian was. Ian was ____ (bad) injured and could not move. They had to wait and ____ (hope) that someone would come and help them. As the evening grew ____ (dark), Ian told Jeremy to leave him and go back to their parents, but he still did not leave. Jeremy thought ____ was not safe for Ian to be alone. The night was cold and windy, and Jeremy used his jacket and extra shirt to keep Ian warm.

    At sunrise, Jeremy decided that the only way ____ (help) his friend was to carry him. So they started the long climb back to their parents. Finally, after four hours, they arrived at the campsite ____ their parents were waiting, “I'll always remember what Jeremy did for me.” said Ian. “He saved my life.”

因式分解：

（1）3a²﹣27                         

（2）a³﹣2a²+a

（3）（x²+y²）²﹣4x²y²

（4）a²（x﹣y）+16（y﹣x）