Is this your pencil box ____ the lost and found box ?

this is your pencil Is this your pencil?是什么意思? Is this pencil your?改错 This is your pencil.(改为一般疑问句) Is this your pencil case中文 is this your pencil-box?的答语 Is this your pencil?中this是什么词? Is 【this】 your pencil-box.问为什么用this. Is this your pencil?Yes ,it is.变复数 This is my pencil ,and that is your.改病句 pencil,your,this,is,sharpener如何合成一个句子? Exuse me!Is this your pencil case?改为复数形式 this is your pencil sharpener.变复数________your___________ Is this your pencil?Yes,t( )you填什么单词 This is your pencil sharpener.改为一般疑问句 is this a pen ___ your pencil case This is your pencil .Here are you .改正 This is a new pen.( ) it in your pencil case