A:卫星的轨道可能为a
B:同步卫星的轨道只能为
C:卫星的轨道可能为c
D:卫星的轨道可能为d
Let's go and play ____ ping-pong.
下列各句中,加横线的词语运用正确的一项是( )
—You'd better do more speaking.
Did it ever ________to you to contact the police when you saw the suspect?