题干
The new school _________ in the past five years.
A：built
B：has been built
C：has built
D：will be built
答案(点此获取答案解析）
D
The new school _________ in the past five years.
A：built
B：has been built
C：has built
D：will be built
，则曲线C的直角坐标方程是 （ ）