he's been collecting matches since he was ten years old.为什么是He’s been 、、、?这是什么意思呀?不是应该是 has been 吗?

连词成句：collecting,since,years,ten,old,was,he's,been,matches,he collecting,since,years,ten,oid,was,he's,been,matches,he 连词成句 What does Bob collet.He collects kites.How long has he been collecting kites.He's been kites sinc he's been collecting matches since he was ten years old.为什么是He’s been 、、、?这是什么意思呀?不是应该是 has been 吗? has watches collecting grandfather young he his been old since was连词成句 Bob has a great collection of shells. He has been ___shells___ three years. A.collected,since B.collecting,about C.collect,during D.collecting,for collecting coins is Mike's hobby;he thinks it's very______(interesting or interested) BOb has been collecting kites__?A since 4 years agoB since he was ten years oldC for 4 years He has been collecting some sand from many places.是什么时态?是现在完成进行时吗? Tom has been collecting stamps since接：he ten years old（be）用括号的动词填空 hong long have you been collecting She has been collecting stamps谢谢了 I've been collecting them for five He's been中的He's 怎么发音He has been 缩写时He's been,He's 怎么发音 是不是[hiz] She has been collecting stampsл!She has been collecting stamps谢! 英语语法 he has been tested 能否缩写成 he's been tested 如果不能 he's been tested是什么时态 collecting collecting