Two weeks ago, on a hot summer afternoon, I was about to cross a little busy road when I noticed an old grandpa with a heavy bag on his back just a few meters from me.

两周前，一个炎热的夏天的下午，我正要穿过一条有点繁忙的马路，这时我注意到一位背着一个沉重的包的老爷爷就在离我几米远的地方。