题干
—Mum, where is my raincoat?
—Oh, I forgot to tell you．It ___ behind the kitchen door．
—Oh, I forgot to tell you．It ___ behind the kitchen door．
A：would hang
B：has hung
C：is hanging
D：hung
答案(点此获取答案解析）
C
是二元一次方程组的解，则这个方程组是（ ）