It's not going to be a backscatter event if your ping-pong ball hits the frame or these strings, or the top part.
打到原子核了就是背散射，如果打到框上。
2
She could have extended the frame even more through the path of the ball, but I think the fact that she didn't is probably because she's added topspin to this shot.
她可以增加自己的攻击线路通过球的线路，但是我想她可能没有这样做，因为她给这个球增加了上旋。
3
The ball has left the frame, but Djokovic is still completing his long follow-through.