would you like a cup of tea___shall we get down to business right away?A and B.then C or D otherw
2.翻译：Do as you have been told ,otherwise you will be punished.
3.it was not until 1920__regular radio broadcast began.A.while B.which.C.that D.since(解释,并翻译）
4.it was not __she took off her dark glasses __i realized she was a famous film star.
A.until .that B,until when (为什么选A不选B,并翻译）