(2018襄阳改编) Be quick, ________ we'll fail to catch the school bus.
A.and B.but C.or D.so
(2018百色改编) ________Wu Lan is still young, she can help her mother do some housework on weekends.
A.After B.Until C.Though D.Unless
(2018青海改编) Learn more reading skills, ________ you'll be a good reader.
A.and B.or C.but D.so
I can lend my bike to you ___________ you promise to take good care of it.
A. while B. if C. although D. unless
The sky is much bluer ________ we have taken action to protect the environment.
A.because B.before C.until D.unless
Taxi Apps（打车软件）can help us travel around more easily. ___more and more people like using them.
A.Or B.So C.And D.But
