A:哥伦布
B:加加林
C:麦哲伦
D:杨利伟
关于银镜反应实验的下列说法中,正确的是( )
在斜二测投影下,四边形ABCD是下底角为45°的等腰梯形,其下底长为5,一腰长为2,则原四边形的面积是____
—Do you know that China is one of ________countries in the world? —Yes, I do. It's much ______than the US.