Four years of negotiation ended fruitlessly last December.历时4年的谈判在去年12月无果而终。The donkey became extremely angry and tried hard to kick the tiger but fruitlessly.毛驴很愤怒，尝试着用蹄子踢老虎，但没成功。...
Categorise the plants into four groups.把这些植物分成4类.This type of china is rather hard to categorise, it's very unusual.这种瓷器非常特殊, 很难归类.This type of china is rather hard to categorise,it’s very unusual.这种瓷器非常特殊,很难归类。Lind...