问题
选择题
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
答案
答案：B
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。