问题: Whydoestheauthormentionasteamship?
A: Toillustratethatmancanmakeuseofsourcesofenergyfromthesea.
B:Toshowthatasteamshipisbetterthanotherkindsofships.
C:Toarguethatmanshouldusesteamships.
D:Toindicatethatitiswarmerintheoceanthanonland.
微信扫码获取一对一帮助