送交者: skipper3 于 2005-11-12, 18:57:41:
回答: 那是因为你可能没有在车行进过程中在D和D1和D2之间换的习惯 由 HunHunSheng 于 2005-11-12, 18:47:31:
needs to go up and down the hill while carrying a big load. But I don't think one should shift around frequently when the vehicle is moving.