They didn’t go to bed ______ the work was finished.
A．when B．while C．until D．after
The famous writer wrote a novel ______ this story.
A．to base B．based upon
C．was based upon D．to base upon
What a tight football game! We lost it ______ we all tried our best.
A．because B．though C．until D．unless
So far, he ______ three languages.
A．learned B．has learned
C．will learn D．was learned
He ______ playing the piano when he was very young.
A．shows an interest B．shows an interest in
C．showed an interest in D．showed an interest
The ______ boy is my neighbour.
A．15-years-olds B．15-year-old
C．15-year old D．15-years old
