用排除法,首先我不确定on condition that后面是否可用类似于should的省略形式,但是如果你选C为何不选A,their names will not be used is wordy 且B,C的时态与spoke不对应,所以排B,C . on condition that是固定短语,排D,E
用排除法,首先我不确定on condition that后面是否可用类似于should的省略形式,但是如果你选C为何不选A,their names will not be used is wordy 且B,C的时态与spoke不对应,所以排B,C . on condition that是固定短语,排D,E