图书馆是确保消防安全的重要场所,据此判断图书馆不需要出现的图标是( ) ① ② ③ ④ ⑤
A:①②③
B:①④
C:③⑤
D:③④⑤
—I'm going to the bus station to _________ my aunt.
Look out! The traffic is _______ fast _______ we can't cross the street now.
关于拉丁美洲叙述正确的是( )
如图所示,在底边为定长b的直角斜面中,球从光滑直角斜面顶端由静止滑到底端,若要下滑时间最短,斜面的倾角为多少度( )