A:MnO2
B:H2S
C:稀盐酸
D:NaHCO3
关于地球半球的叙述,正确的是( )
——The relation between the two countries gets _________. A war seems to break out soon .——I hope they will make peace with each other .
以原点为中心,把点P(1,3)顺时针旋转90°,得到的点P′的坐标为( )