Mysister,aninexperiencedrider,wasfoundsittingonthebicyc...

My sister, an inexperienced rider, was found sitting on the bicycle______to balance it.

A. having tried B. trying C. to try D. tried

解析此題考查非謂語動詞的用法。句中的空格處動詞與主語my sister構成主動關係，即try這個動作是my sister發出的，所以用trying表示她主動“設法/嘗試着保持自行車平衡”。