直接reading,这个叫ing形式表被动
类似的还有the car needs repairing＝the car needs to be repaired直接ing就可以了.
有时不定式也有这种用法,如You have a lot of homework to do这里作业是被做的,但直接就用不定式了,用to be done其实也可以,但意思就产生了变化.to do是你自己做,to be done是让别人做.