北京市的别称是
A:购物天堂
B:东南侨乡
C:祖国心脏
D:天涯海角
如图,AB是半圆的直径,点D是弧AC的中点,∠ABC=50°,则∠DAB等于( )
— Mr. Li will check our homework this afternoon. _______ you _______ it?
— Not yet. I'm doing it right now.