Mr. Black has been teaching English in a middle school he came to China.
A. for ever
B. ever since
C. since then
D. long before
网友回答
A. for ever
(答案→)B. ever since
C. since then
D. long before
解析：本题考查连词词组。for ever永远，总是；ever since从那时到现在；since then以前；long before很久以前。句意：布莱克先生从他到中国到现在他一直在一所中学教英语。