I can only give you another two hours/days/weeks/minutes.

我只能再给你两个小时/两天/两个星期/两分钟。

I need to have it by lunchtime.

你得在午饭时间之前给我。

I need it on my desk by this afternoon. 

在今天下午之前，必须放在我桌子上。

I have to have it no later than Friday at two P.M. 

必须在星期五下午两点之前给我。

You have to have this done by tomorrow. 

你必须在明天之前把它完成。

Let's get this done. Let's get this over with. Let's get this taken care of. 

咱们把它做完吧/咱们赶快把它解决

Let's take a break. It's break time. It's time for a break. 

咱们休息一下吧/该休息了

Let's take a coffee break. 

咱们喝杯咖啡休息一下吧。

I need to get out and stretch my legs/rest my eyes/clear my head.

我得出去拉伸腿/休息一下眼睛/让脑袋清醒一下。

I need to get out of the office for a little while. 

我得到办公室外面呆一会儿。

Dialogue:

A: How about taking a break and talking about this over coffee.

你觉得咱们休息一下，边喝咖啡边讨论怎么样？

B: Sounds good, we're not getting much done just staring at the computer. 

好主意，我们盯着电脑并没有什么进展。