Question

你能冒险一个人旅行，真是勇敢。

____________________

Answer

It was brave of you to risk traveling alone.

【解析】

此处的主语是动词不定式“冒险一个人旅行”，用it做形式主语，讲述“做某事某个人是……的”用it be+形容词+ of sb. to do”。句子讲述过去发生的事，用一般过去时态，用it was。勇敢的用形容词brave。表示“冒险做某事”用动词短语risk doing。“一个人旅行”用travel alone。故答案为It was brave of you to risk traveling alone.