他的手背因为摔倒划伤了。

The ___back of his hand was scratched from the fall.

他靠在椅背上放松。

He leaned against the chair to relax his ___back.

我把钥匙挂在门后面了。

I hung the keys on the ___back of the door.

她慢慢往后倒车，避开那棵树。

She carefully ___backed the car to avoid hitting the tree.

许多家长都支持学校的新教育政策。

Many parents ___back the school's new education policy.