this pair of glasses是复数还是单数

this pair of glasses是复数还是单数 this pair of shoes 是单数还是复数? this pair of trousers作主语是单数还是复数 This pair of trousers____(be 1.是This is a pair of glasses 还是They a pair of glasses pair是单数还是复数? three glasses of water谓语动词是单数还是复数? a pair of glass是单数还是复数? a pair of pants 是单数还是复数 a pair of是单数还是复数概念? this pair of glasses may be is his 还是 this pair of glasses m This is a pair of glasses 变为复数 The pair of glasses ___ not for Lucy.用单数还是复数形式?为什么?象“裤子”这类的呢