Mr. Black walked around and offered help ________ we were doing an experiment.
A.although B.when C.until D.unless
He kept going on his trip ________ he was very hungry and thirsty in the desert.
A.although B.whether C.unless D.as
I didn't know the news ________ you told me. Thank you for telling me that.
A.because B.though C.until D.while
My father was preparing for his speech __ my mother was doing some washing last night.
A.if B.while C.unless D.until
Our world will get better and better each of us lives a greener life.
A.before B.if C.though D.until
Eric arrived on time, _______ it was the rush hour.
A. though B. because C. while D. unless
