The twins are so much alike that their own mother can hardly ______ them ______ .
Could it be in the room _________ we had a talk last night ___________ you left your keys ?
Those books were _______ adults, so it’s unnecessary for teenagers to digest them carefully.
--You seemed to be impressed by his skill. ---No. It was his courage ________ his skill that really impressed me.
This is the best way I could think of ______________ into the dangerous area.
The news that he failed in the exam _____________ his unhappiness this morning.