阅读下列各小题，根据括号内的汉语提示，用句末括号内的英语单词完成句子，并将答案写在答题卡上的相应题号后。
71．Expo 2010 Shanghai China ____________________ (在召开)on both banks of the Huangpu River in the city of Shanghai, China, from May 1 to October 31, 2010.（hold）
72．The official song of the 2010 World Cup in South Africa titled Waka Waka features many musical elements that_____________________（追溯到）the ancient times.(date)
73．He looks sleepy. He must_____________ (熬夜了)last night, writing the essay. (stay)
74．— Is Bob still performing?
— I’m afraid not. He is said ______________（离开）the stage already as he has become an official.(leave)
75．_________________ (适应) the tropical heat was more difficult than they had expected. (adjust)
76．When the survivor woke up, he wanted to know ____________ (是谁) that saved him from that burning house. (who)
77．The more ways we have of looking at a problem , ____________________ （越有可能）that we can find a solution. (likely)
78．His younger sister teaches in a secondary school, in front of _______________ (流淌着一条小河). (flow)
79．It is possible that the King of Stonehenge was linked to the stones: he __________________
(很可能参与了) in planning the monument, or in helping transport and pull up the stones. (hand)
80．Representatives attending Copenhagen Conference recommended that _______________ (采取严厉措施) to reduce carbon emission. (take)