When you are doing it, do you lose track of time?
是否每当你做这件事情的时候就会忽略了时间？

You lose track of time when you're engrossed in the activity.
当你投入到那项活动的时候，你就忘记了去看时间。

I do a lot of reading, and one of the few downsides to that habit is that I often lose track of the source of an idea or phrase.
我会读很多东西，这个习惯带来的一个缺点是经常遗漏某个想法或词组的来源。

5. supposed to be: 本应如此

You were supposed to be here an hour ago.
你应该在一小时之前赶到这里。

Because the truth is, I’m not supposed to be here, standing here.
因为事实上我本不应该在这里、不应该站在这里。

IMITATION is supposed to be the sincerest form of flattery, but that is not how most brands see it.
模仿应该是一种最真诚的恭维，不过这可不是大部分的品牌厂商所乐见的。

6. fall in love: 陷入爱河(爱上,喜爱)

Some fall in love with the West and decide to stay, if they can wangle a visa.
有些人则和西方人坠入爱河并决定定居国外，如果他们能想法弄到签证的话。

Scientists have found that the parts of the brain that are activated when we first fall in love are re-stimulated by adventure and novelty.
科学家发现当我们第一次坠入爱河之后，我们的大脑就会受到新一轮的刺激，对冒险以及其他的新奇的事物感兴趣。

Yet the story, simple in format, was passionate and brave: two women, one a doctor, the other a carpenter, fall in love and decide to bring a child into the world and raise her together.
但是这个形式简练的故事，却充满了真情与勇气：职业分别是医生和木工的两个女人坠入爱河，决定生育一个孩子并共同将它抚养成人。

7. kill off: 消灭，杀光

This is to make sure you kill off as much of the bacteria as possible the first time around.
这么做是确保在第一轮的时候就尽最大可能的去消灭所有的细菌。

Kill off the Goddamned cowards and we will have a nation of brave men.
干掉那些遭天谴的懦夫我们就会有一个国家的勇者。