While we _______ football in the classroom, the teacher came in.
A:were play
B:were playing
C:are playing
D:played
某家庭用燃气热水器将质量为100kg,温度为20℃的自来水加热到50℃,消耗的天然气体积为1m3(假设天然气完全燃烧).已知水的比热容为4.2×103J/(kg•℃),天然气的热值为3.2×107J/m3.求:
由四舍五入法得到的近似数8.8×103,下列说法中正确的是( ).
6+6=____