—Did Jack come back early last night?—Yes, It was not yet eight o’clock _____ he arrived home.
The university started some new language programs to _____ the country’s Silk Road Economic Belt.
It is so cold that you can't go outsidefully covered in thick clothes.
_____ Li Bai, a great Chinese poet, was born is known to the public, but some won’t accept it.
Much time _____ sitting at a desk, office workers are generally troubled by health problems.
-Jim, can you work this Sunday? -? I've been working for two weeks on end.