题干
I can't remember ________ I put the book, and I need it for my homework now.
A：where
B：how
C：what
D：why
答案(点此获取答案解析）
A
I can't remember ________ I put the book, and I need it for my homework now.
A：where
B：how
C：what
D：why
是两个不同的平面，m，n是两条不同的直线，给出下列命题：
；
； 
相交；
