沒有頻繁的意思是,hard,意思是困難的、堅硬的,例如:
1、The substance polymerizes to form a hard plastic.這種物質聚合形成堅硬的塑料。
2、The cutters have very hard teeth made from special steel or from diamonds.刀具上有用特種鋼或金鋼石製造的非常堅硬的齒。
3、Granite is a very hard stone.花崗岩是一種很堅硬的石頭。
沒有頻繁的意思是,hard,意思是困難的、堅硬的,例如:
1、The substance polymerizes to form a hard plastic.這種物質聚合形成堅硬的塑料。
2、The cutters have very hard teeth made from special steel or from diamonds.刀具上有用特種鋼或金鋼石製造的非常堅硬的齒。
3、Granite is a very hard stone.花崗岩是一種很堅硬的石頭。