Mr black is principal of school ,_____an expert in translation

Mr black is principal of school ,___as__an expert in translation.
布兰克先生是学校的校长,身份是一位翻译专家.可以填别的什么词吗？比如while 之类的？while是引导句子的，而后面是一个名词词组。别的词我还没想到哦。