前面是Is this your eraser

前面是Is this your eraser Is that your mother为什么Is要在that的前面.This is your mother/is在this后面? is this your book?为什么this前面用is?快速回答! 是is this schoolbag your还是is this schoolbag yours Is this your sister?的答语是? is this your sister的答语是 is this your sister 的肯定回答是?is this your sister 的肯定回答是? is this your skirt this is your Maybe this is your Is this your uncle? this is your aunt. is this your business Is this your schoolbag? Is this your (空格) Is this your schoolbag? this is your pencil Is this your cake.