The math problem was ________ difficult for me ________ work out. [ ]

Some young people like reading novels on their mobile phones after turning off the light at night.—Don’t you think it is to their eyes?

He _____ be at home, because the light is on.

My father usually ________ a shower ________ ten in the evening. [ ]

Leo was so __________that he rushed to the kitchen ,hoping to find something to eat.