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.
小明在实验室利用天平、量筒、烧杯测量盐水的密度,其方法和操作过程完全正确.
看图列式.
____ ____ ____=____
小方、小红、小冬比赛了三次,成绩记录被墨水弄污了。