Sheila isunderstood ------ won the first prize

Sheila isunderstood ------ won the first prize Sheila is understood won the first prize won the first prize=won first prize? 为什么是Who won the first prize? 到底是won the first prize对还是won first prize 对 求解 Jhon won the first prize in the contest. — I won the the first prize of Natioal English speaking Jenny won the first prize in the race 1.John won the first prize in the contest.___ The running boy won the first prize 这个句子对吗. Peter won the first prize in the English speech competition He was the first one who won the prize