有关地球自转的描述,错误的是( )
A:地球自转方向是自西向东
B:地球自转产生了昼夜更替
C:地球自转产生了四季更替
D:地球自转周期约为24小时
竖直升空的火箭,其v﹣t图像如图所示,由图可知以下说法中不正确的是( )
_____the difficulties in talking, they can understand each other by body language.( )
—Tommy looks so tall.
—That's right.Tommy is known as the tallest boy in our school.