两个相似五边形，一组对应边的长分别为3cm和4.5cm，如果它们的面积之和是78cm²，则较大的五边形面积是（　　）cm²．

古诗鉴赏，按要求答题。
                                                                                                                              己亥杂诗 龚自珍 清
                                                                                                                  浩荡离愁白日斜，吟鞭东指即天涯。

                                                                                                                  落红不 是无情物，化作春泥更护花。

阅读短文，选择正确的答案。

    I am seven. I go to school every day. Classes start at eight o'clock. In the morning. I have Chinese, Art and Maths. I have English and P.E. in the afternoon. I get home at half past four. I watch TV at home. I have a good friend, Xiaotian. He sleeps at school. He goes to bed at nine. I go to bed at half past nine.

2009年“世界环境日”提出“团结起来应对气候变化”。下列做法不能减轻温室效应的是（　　）