我们赶飞机太匆忙了，我想我一定是把钥匙落下了。

In our rush to catch the flight, I think I ___left my keys ___behind.

疏散时，他们不得不留下珍贵的家庭照片。

When evacuating, they had to ___leave ___behind cherished family photos.

搬到一个新城市意味着要离开我所有的童年好友。

Moving to a new city meant ___leaving all my childhood friends ___behind.