... to open the bag. Because the bag stands up, it is easy to put things in it. Paper is very common in our lives, and we don’t even think about it, but it is a wonderful invention. T F1. Check ... tie it with string. Other customers had to wait. Then they hired boys to make bags by hand, but this also took a long time. In 1884, a woman named Mattie Knight invented a machine that could ... b&c8. She asked me………………a. stop playingb. stop to play c. to stop playing d. stopping to play 9. I am going to visit you Thursday.a. in b. on c. at d. of Marks Teacher’s comments10. Tuan...