what's this?It's a pen.为什么不能说是"this is a pen.我们老师说就是不能说this is a pen.为什么

-What's this?-It's a-------. 英语翻译what's this?it's letter p.what color is it?it's green.what's this and what color is it?this is letter e.it's yellow .what's this letter?it's letter n.it's red.p-e-n.is it apen what's this?it's a chair.怎么翻译. What's this?It's a pen.(改为复数句) what's this?it's a cat变为复数句 What`s this in E( ) It`s an a ( ) 选择题What's this?A.It's Z.B.It's red.C.This is ruler. 选择 What's this - ( )A A.It's B.It's an C.It's a D.This is What's this?It's letter P.what___is it?It's green.white.what's this letter?It's sletter N.It's red.P-E-N.is it''____''?Yes,it is.I have__blue pen .it's____to What（ )this?It's( )apple What's this( )a photo?A.It's B.it's C.Its What's this it's bag.对么 What's this ( ) Chinese It's jiakeshan. It's coffee.__?It's milk.A.Who is this B.What's it.C.And what's mine D.And what's this 选哪个 what 's this with English?It's a pen a.what 's b.with c.It's 挑错并改正 what's this?It's V.为何不回答说it's a V呢? A:What's this?B:Oh.( )It'sA:What's this?B:Oh. ( )It's my pencil. What's this in English?What's this letter?What's this in English?It's VIt's a VIt's an VWhat's this in English?It's HIt's a HIt's an HWhat's this in English?It's UIt's a UIt's an UWhat's this letter?It's VIt's a VIt's an VWhat's this letter?It's HIt'