答案：C
下列关于地球运动的说法，正确的是
A．地球自东向西自转
B．地球自东向西公转
C．地球公转周期为一年
D．地球自转周期为一年
They went into the room and saw a large piano standing____ the wall,covered with thick cloth.
A．against
B．onto
C．behind
D．on
