Ask a few questions about the history of grade one.

1C (in fact, it has a high shipping value)

There is a large population in the east and a small population in the west ... (obviously ...)

3( 1) has a long longitudinal span.

(2) the latitude span is large

(3) Because the east-west longitude of our country spans nearly 60 degrees.

Because I have crossed the north-south latitude of nearly 50 degrees. ...