is this 和this is用法有什么不同?

is this 和this is用法有什么不同? is;am用法有何不同.This is; 和This are用法有何不同. here is 和 this is 用法上有什么区别 Is this的用法 that is why和 this is why用法的区别 this is 和 here is 在用法上有何区别?先谢谢诸位了,呵呵. Is和 This在语法和用法上有什么区别 who is this和who is that有什么区别?请讲清楚点,用法有什么差别?要例子的 但是我看过：Who is this?A.This is Jack.B.That is Jack.要选哪个?为什么? a和an的用法This is( )book This is( )eraser This is( )Englishbook This is( )dictionary This is( )notebook This is( )encyclopdia 在（ ）填a或an this is的用法急不要造句 This is according to...这种用法对吗? 人名加’是不是和名词性物主代词有一样的用法比如,this handbag is mine This handbag is Tom’s第二句话这样用可以吗 this is和this are的区别 This开头和 It is开头用法的区别例；This si a pen和It is a pen This is is this This is THIS IS