Despite their extensive efforts to determine the mode of oil ___, scientists still have not ___the process by which oil is produced.
这两个选项:
1. creation investigated
2. genesis established
我做的时候选的1.因为看到extensive efforts to determine, 而第二空应该是没下功夫去研究,但是答案是2.解析说establish 对应determine,1的第二空不合题意, 这答案也太不清楚了吧, 为什么不合题意。