Ill run back over the procedure once again.
我将重新考虑这个程序。
Its a lot of information to absorb all at once.
要一下子消化这么多资料,真是很难。
If necessary I can come at once.
如果有必要,我可以马上来。
A computer can perform many tasks at once.
电脑能同时做多项工作。
Since the party she had only spoken to him once.
那次聚会以后,她只和他说过一次话。