—We're going to have a soccer match with Class 2 this afternoon.
—_______.
A:Thank you
B:Good luck to you
C:Not at all
D:It doesn't matter
如图,河对岸有铁塔AB,在C处测得塔顶A的仰角为30°,向塔前进14米到达D,在D处测得A的仰角为45°,求铁塔AB的高.
欧洲最长的河流是( )
以下用于研究有机物的方法错误的是( )