-- What were they doing at that time yesterday?
-- They .
A：play soccer
B：played soccer
C：were playing soccer
看拼音，写汉字。
tī qiú shǒu qiāng shāo shuǐ
____ ____ ____
guǐ zi xí guàn dǎ gǔn
已知关于x的一元二次方程x2+5x+3﹣3m=0有两个不相等的实数根．
在西北的____ 、____ 、____ 和天山山麓，人们利用____ 和高山冰雪融水，发展了____ 农业．
