His father suddenly died off that he is very sad.意思是什么?

相关推荐

• Bob King is an English boy.He is 13.He is a student of No.1 Middle School.Look!This is a photo of his family.The boy is Bob.He is smiling（微笑）.The girl is his sister.Her name is Lily.She is only 7.His grandparents are old.But his parents are young.Linda is his mother.She is beautiful.She is a housewife.His father,Ben,is a businessman.He works hard.Bob has a happy family.He loves it very much.想问下He works hard在这里是什么意思?还有就是Bob has a happy family那里为什么用has?
• His father suddenly died off that he is very sad.意思是什么?
• 证明：tanαtan2α+tan2αtan3α+……+tan(n-1)αtan(nα)＝tan(nα)/tanα-n
• 最早向中国人介绍进化论的人