This pencil is 18cm.That pencil is 20cmThis pencil is a ___ ____ than that one

This pencil is 18cm.That pencil is 20cmThis pencil is a ___ ____ than that one this is your pencil Is this your pencil?是什么意思? Is this pencil your?改错 This is his pencil case. This is a pencil box.对a pencil box 提问 This is a pencil box.(对” a pencil box”提问 ) This is your pencil.(改为一般疑问句) this is a pencil 改为一般疑问句 This is my pencil改成一般疑问句 Is this your pencil case中文 this is his pencil case 复数句 This is my pencil.换成一般疑问句. Is this pencil box?(改为陈述句) this is a pencil改为复数句 --- () is this?--It's a pencil 改为复句this is my pencil box is this her pencil box?改为陈述句