(2019苏州)Love your parents ________ they are alive. Don't wait until it is too late.
A.while B.though C.because D.unless
(2019滨州)Emily, you're playing video games again！Study hard，________ you will fail in the coming exam.
A.then B.so C.and D.or
(2019安徽)Our business won't improve ________ we offer better services to our customers.
A.because B.unless C.after D.since
(2020原创)I respect my parents, ________ sometimes I just can't agree with their old opinions.
(2020原创)My parents were not at home, ________ I had to look after my 5yearold sister.
(2020原创)You may do the survey yourself ________ work with someone else together.
