给下列句子选择合适的答语。
① It's 7 o'clock ____ A. It's time for English class.
② It's 9 o'clock ____ B. It's time for breakfast
③ It's 5 o'clock. ____ C. It's time to go home.
你想喝橙汁,你问
4520000000≈____亿
为上联“心平浪静,秋月芙蕖湘水碧”选择下联,最合适的一项是( )