C1881 Trading for Heavy Cards

"Di, Di!" Two horns sounded out from the Excavating Machinery.

As long as he passed through it a few times, he would be able to get familiar with it. The Excavating Machinery's master would press it twice and drive over in the air. When he fell in the most suitable position, he would press the horn. At this time, it meant that the empty car was parked in place.

Of course