is this mary‘s doll?将句子变成复数

is this mary‘s doll?将句子变成复数 将下列句子变成复数形式：This is my sister. whose knife is this?将句子变成复数 小题1:That is Mary’s photo.（将句子变为复数句）_______are Mary’s________ 将句子变成复数形式4、 将下列句子变成复数形式1) This is a bus .2) She has a nice d This is tom'S friend in america.改为复数形式 This is mary's father 将下列句子中的词变成复数形式 this is a brush.that is a tomato.she has a ni 以下句子变成复数句Is this your ruler?yes,it is.It's his backpack.What 将下列句子改为复数形式 (1)this is a pretty dress.(2)lt's a this is not my umbrella.把句子变成复数形式 把下列句子变成复数形式.This is a watch. this is a bix.变成复数的句子怎么变