Go in the project, drag the sprites in your back pack (first open back pack) then there, you drag it back to your project!
I have return to Scratch! after years, coming back feels good! i am now 17 years old (birthday 12/06/2003) and it feels so good to be back! i learn more and know more, i came back just for memorys and it got me to go back and making projects. i will be making better ones. go to my youtube if you want to see me! https://www.youtube.com/channel/UCP-3BZTj6bX2OMA5xCN5sMg