问题补充：
— What a shame ! It turned out to be a failure.
— We missed a process, we could not succeed in the experiment.
A. and otherwise
B. and therefore
C. or perhaps
D. but luckily
答案：
A. and otherwise
(答案→)B. and therefore
C. or perhaps
D. but luckily
解析：考查连词，and otherwise意思“否则”，and therefore意思“因此”，or perhaps意思“或许”，but luckily意思“但是幸运的是”，句子意思“我们丢失了做事方法，因此我们将不会做试验成功”
