and 05:17:38 UT. The blue arrow in the panel (a) indicates the brightening in H$\alpha$, while the white dotted lines indicate the same path for the time-distance diagrams in pane (e). (c)-(d) $SDO$/AIA 304 $\rm\AA$ images at corresponding time. (e) The time-distance diagrams derived from a series of H$\alpha$ images from 05:02 UT to 05:56 UT. \[fig3\]](figure3.eps){width="\columnwidth"}

Fig.\[fig4\] exhibits another material injection event during the period from about 05:51 UT to 06:35 UT. Panels (a) and (b) show this material injection event in H$\alpha$ images observed by the NVST at 05:59:00 UT and 06:11:19 UT, respectively. We also find some brightenings in the vicinity of the filament south-western footpoint, which are marked by the blue arrows. However, we also can not distinguish any brightenings at the corresponding places in $SDO$/AIA 304 $\rm\AA$ images in panels (c) and (d). This jet is also associated with H$\alpha$ jet instead of EUV jet. This means the cool plasma were ejected by the jet and injected into the filament, which is similar to the previous event. We also make a time-distance diagram to estimate the velocity of the ejected cool plasma along the white dotted lines in the panels (a) and (b). Panel (e) 