在空间直角坐标系Oxyz中,点P(1,﹣2,3)关于x轴的对称点的坐标是( )
A:(﹣1,2,﹣3)
B:(1,﹣2,﹣3)
C:(1,2,﹣3)
D:(-1,﹣2,3)
① What are you doing? ____ A. No,she isn't.
② What is your mum doing? ____ B. Yes I am.
③ Can I use your pen? ____ C. I'm cleaning my room.
④ Is Sarah reading a book? ____ D. She is cooking fish.
⑤ Are yoy doing homework? ____ E. Sure.
如图,在4×4的正方形网格中,cosα=( )
下列各项文学常识搭配不恰当的一项是( )