—So hard _____ in the past few months th
题型：选择题
问题：
—So hard _____ in the past few months that he has made great progress in English.
—I can see that; only a few mistakes _____ in the exam.
A．has he worked; did he make
B．he has worked; did he make
C．he has worked; he made
D．has he worked; he made