海滩上那位孤独的步行者陷入了沉思。

The ___solitary walker on the beach was lost in thought.

没有部队，这位将军只是战场上一个孤零零的士兵。

Without his troops, the general was just a ___solitary soldier on the battlefield.

那座孤零零的灯塔守卫着空荡的海湾。

The ___solitary lighthouse stood guard over the empty bay.