By next summer John in this factory for thirteen years.
A. has been working
B. will have been working
C. will be working
D. has worked
网友回答
A. has been working
(答案→)B. will have been working
C. will be working
D. has worked
解析：考察时态。本题的关键是by到…时为止；该词通常与完成时连用，本句后面的时间状语是next summer,这是一个将来时的时间状语，故本句使用将来完成时。句意：到今年夏天结束的时候，John将在这家工厂里工作了13年了。故B正确。