— Have you heard of Earth Day? — Yes. Th
问题:
— 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
— 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