I visited many places including the History Museum last Saturday. When I _______ at the hotel, it was very late.

阅读《浣溪沙》，根据要求回答问题。
                                                                                                                                 浣溪沙
                                                                                                                                   晏殊
                                                                                           一曲新词酒一杯。去年天气旧亭台。夕阳西下几时回？
                                                                                           无可奈何花落去，似曾相识燕归来。小园香径独徘徊。

如图为中国居民的“平衡膳食宝塔”，请据图回答问题。

选取生长正常的爬山虎进行如下图所示的光合作用实验：

①实验前应将此装置放在黑暗处一昼夜后，移至光下几小时，再将甲、乙、丙三片叶取下，分别放入盛有酒精的小烧杯中，隔水加热，使叶绿素溶解到酒精中．

②将叶片用清水漂洗后放入培养皿中，分别向这三片叶上滴加碘液，观察三片叶是否变蓝．