heavy current lead-in

例句：

1. 1. The heavy rain caused the roads to be impassable.
   大雨导致道路无法通行。
2. 2. He carried a heavy load on his back.
   他背着一个沉重的负担。
3. 3. The heavy snow made it difficult for us to move around.
   厚厚的积雪让我们难以移动。