(2018保定竞秀区二模) Last night I stayed up too late, ________ I'm really sleepy now.

(2018长春改编) Work hard and be patient, ________ your dream won't come true.

It’s hard for us to say goodbye       we have so many happy days to remember.

A.so B.because C.although D.until

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

(2017河北34题)Mom won't let Dick go out ________ he promises to be back by 10：00 tonight.

A.if B.when C.since D.unless