Two girls share a box.This box is_________ A.Mary's and Sara

Two girls share a box.This box is_________ A.Mary's and Sara 1.two girls are mary and linda a.this There （ ）a football and two basketball s in the box There______ a pen and two felt pens in the box. What's this?It's a box.为什么回答中要用It's,而不用this is a box 填空：1.this box is heavier ( )that one.2.it's a heavy box that This is a pencil box.对a pencil box 提问 This is a pencil box.(对” a pencil box”提问 ) Here ’s a box ______ pencils______you and your sister I __ a pencil-box,a pen ,a ruler and two __ . I have a bike, The bag has two books and a pencil-box inside(对划线部分提问)two bo and,has,a,pencil,Mary,three,pencils,box.连词成句。