道教中的三清四御

五年级学生中女生占48%，六年级学生中女生占46%，五年级的女生一定比六年级的女生多．______．

— Have you heard of  Earth Day?

— Yes. The first Earth Day _____ in 1970 to educate us to protect our planet.      [ ]

A. celebrates      

B. celebrated    

C. is celebrated    

D. was celebrated

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