工人们不得不砍倒那棵危险的树。

The workers had to ___fell the dangerous tree.

那个摔跤手轻松地把对手摔倒在地。

The wrestler easily ___felled his opponent to the ground.

约克郡的荒野上纵横交错着古老的石墙。

Ancient stone walls crisscross the ___fells of Yorkshire.