When Jason failed to pay his bill,the network company ________his Internet connection.
A:cut off
B:cut back
C:cut short
D:cut down
下图中阴影部分表示夜半球,A,B两地均处在30ºN,该日某海洋考察船由A向B航行。此时太阳直射点的坐标为( )
张老师讲解下幅知识结构图时最有可能得到的认识是( )