_____ October 1,we will celebrate the seventieth birthday of the People's Republic of China.
介词用法辨析。
根据空格后“十月一日”可知，在某个具体日期前需要使用介词on，故选A。
Our geography teacher told us to _____ more information（信息） about our city and share it next year.
动词短语辨析。
结合本题的语境可知，地理老师叫我们去查找信息，用find out表“查找、弄清楚”，故答案为A。
—Jerry,have you ever been to the Great Wall?
—Yes. I _____ there with my parents last year.
动词时态辨析。
根据last year可知，去长城的动作发生在去年，要用一般过去时，B项went符合。