Have you ever played jokes _____ others _____April Fool's Day?

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。

Once there was a free bird. She floated in the sky,____(catch) worms for lunch and swam in the summer rain trickles(滴), like many ____birds. But she had a habit:____some event occurred in her life, whether good or bad, the bird would pick up a stone ____the ground to memorize it. Every day she sorted out her stones, laughed remembering joyful events, and cried remembering the sad ones.

The bird always took the stones with her, whether she was flying in the sky or walking on ____earth, and she never forgot about them. Years had passed ____the free bird got a lot of stones, but she still kept on sorting them out, remembering the past. It was becoming more and more difficult for her to fly.

The bird was unable to move on her own，____could she catch worms anymore. Only rare rain gave her the necessary energy.But the bird ____(brave) endured all the hardships, ____(guard) her precious memories. After some time the bird died of ____ (starve) and thirst. 

阅读下列材料，回答问题。

材料一：见图。

材料二：战略导弹部队是随着中国导弹部队的建立和发展而发展起来的……1966年7月1日，中国战略导弹部队领导机关在北京宣布成立，周恩来总理亲自为它命名：第二炮兵。

材料三：近年来，中国战略导弹部队取得了近千项科技成果。导弹自动化测试系统的研制成功，使部队测控技术一步跨入世界先进行列；……经过20年的发展，中国战略导弹部队武器装备初步形成固体与液体并存，核导弹与常规导弹兼有，近程、中程、远程和洲际导弹齐备的武器系统。