solitary

他喜欢在公园里独自散步。

He enjoys taking ___solitary walks in the park.

黎明时分，那条小径上只有一名跑步者在锻炼。

At dawn, the path was used by a ___solitary runner.

那是一次穿越印度的为期一个月的独自旅行。

It was a month-long ___solitary journey through India.