To our delight, up till now, the European Union, Japan, and Russia their targets for CO2 emissions (排放).
A. give
B. have given
C. give
D. gave
网友回答
A. give
(答案→)B. have given
C. give
D. gave
解析：考查时态。句意“让我们高兴的是，直到现在，欧盟、日本和俄罗斯已经制定了二氧化碳排放的目标。”up till now相当于so far，与现在完成时连用。故选B。