The old lady didn't know___when the house caught fire.A how

The old lady didn't know___when the house caught fire.A how The old lady didn't know___when the house caught fire.为什么选C啊 1.The old lady didn't know ( ) when the house caught fire the old lady didn't know ___ when the house caught fire. He didn't know ____when the house caught fire.A how to do it he didn't know_____ when the house caught fire.A.what to do The old lady did not know ____when the house caught fire. The girl didn't know（）when the house caught fire.填空 14.The old man didn’t know _______ when the house caught fir I didn't know how the house————（catch）fire The old lady did not know ___________when the house caught f The house caught a fire.The firemen carried the wounded man