for a long time after the operation,Linda found ________difficult to fall asleep

问题描述:

for a long time after the operation,Linda found ________difficult to fall asleep
A this b,one c that d,it 选哪个,为什么

it
形式宾语,指代to fall asleep如果形式宾语IT主语不是要放在句子后面的嘛,主语是哪个啊,本人英语不太好,帮帮忙啊,谢谢主语是linda