theoldprofessorgaveordersthat,the.experiment[]before6

theoldprofessorgaveordersthat,the.experiment[]before6
theoldprofessorgaveordersthat,the.experiment[]before6

theoldprofessorgaveordersthat,the.experiment[]before6
the old professor gave orders that the experiment before 6.

B答案 A：没有直接写be finished的说法 C：用了被动时态，不需要用到被动，如果选了，意思变为“必须被结束” D：should后面加原形 选择A答案吧.

什么啊