Estimation of the twist number released by the second jet-like activity. (a)–(c): SDO/AIA 304 Å images at different moments. The white arrows mark the dark structure at a different moment. The dotted-dashed white line outlines the path for the time-distance diagram of panel d. The two black asterisks on the dotted-dashed white line mark the width of the rotation. (d): time-distance diagram reconstructed by SDO/AIA 304 Å observations along the dotted-dashed white line in panel b. The dashed lines mark some dark inclined stripes.