A:0度纬线
B:30度纬线
C:60度纬线
D:90度纬线
图(1)美丽的杭州西湖的面积是5.6____.
图(2)机场跑道占地面积大约是20____.
图(3)这台电脑屏幕的面积大约是7.8____.
下列四幅省区轮廓图中表示黑龙江省的是( )
If steel is heavier than water, why are ships able to on the sea?