题干
—Is there a map in your classroom?
—
A：Yes, it is.
B：No, there isn't.
C：Yes, there are.
D：No, there aren't.
答案(点此获取答案解析）
B
—Is there a map in your classroom?
—
A：Yes, it is.
B：No, there isn't.
C：Yes, there are.
D：No, there aren't.
、β是两个不同的平面，则下列命题中正确的是
