i am s___ this pen is bob's中s?是什么单词

i am s___ this pen is bob's中s?是什么单词 This is Bob`s pen .Please____. --Whose new pen is this?--It is Bob's.这句话是否正确,如果错误就改正 Is this your pen Yes,I think it's her pen. Is this kate`s new pen?回答 This is David's pen,____ . Mike () (think)this pen is bob is Mike's pen pal is from S___.It's in Australia. That is Lily's pen I am fine The orange is orange (否定句 一般疑问句 this is( )my pen.it's( )pen.( )里填空 this is () pen,but it's ()broken pen who is that?A.That's a student B.It's Bob C .This is Bob