The reserch is so designed that once ___ nothing can be done to change it.A.begins B.having begun C.beginning D.begun 为什么选D?

The reserch is so designed that once ___ nothing can be done to change it.A.begins B.having begun C.beginning D.begun 为什么选D? 这个句子的语法和语意该怎么理解?When reserch priorities are being set for science ,educatuin,or anyother area,the most important question to consider is:how many people`s lives will be improved if the results are succesful?When reserch so deep is the so is the sadness The lion is so so is the The word is so policy reserch office of the communist party of china central committee翻译 America's emphasis on the importance of education for everyone has spurred scientiful reserch.全部翻译 The fright time is so so as is the huaband ,so is the The ant is so small. The world is so small, The lion is so strong. So the year is over the city is so empty So cheap the bag is! The happyness is so FAR