嗯...我不确定能不能按时完成这个任务。

___Uh... I'm not sure if I can finish this task on time.

我想想...呃...大概需要20分钟吧。

Let me think... ___uh... it'll take about 20 minutes.

呃...让我想想该怎么回答你。

___Uh... let me think about how to answer you.