If the two media have really different densities, like air and water, then most of the energy is going to be reflected back, very little of it will keep going and get transmitted into the new medium.
而如果这两种介质的密度相差较大，就像空气和水那样，那么大部分的能量将会折射回来，只有一小部分会继续传播进入到新的介质中。
I know that I spent four cents to get you and I want my money back.
我只知道我花了四分钱买了你，我想把钱要回来。
I can get it from my dorm room, bring it back with me and submit it with those forms you need from me.
我可以回宿舍拿，并把它拿回来和你需要的那些表格一起交上去。
Don't overspend on your home and expect to get the money back when you sell.
不要在房子上花费太多，别指望你卖掉房子时还能把这笔钱收回来。
When Mrs. Thrush leaves the nest to get a worm and comes back to feed her young, there are four little thrush mouths and one huge cuckoo mouth.
当画眉鸟夫人离开巢穴去捉虫子回来喂养她的孩子们的时候，就有四张小画眉鸟的嘴巴和一张巨大布谷鸟的嘴巴大张着。
He told these children that they could eat the marshmallow at once, or wait until he came back and get two marshmallows.
他告诉这些孩子，他们可以立即吃掉棉花糖，或者等他回来，然后得到两块棉花糖。
Gradually, this noise began to appear during a show, and to get rid of it, I had to change to another channel and then change it back.
渐渐地，这种噪音开始出现在节目中，为了消除噪音，我不得不换到另一个频道然后再换回来。
I often get emails back from students' posts because I didn't correctly read their handwriting on the email address.
我给学生寄的邮件经常被退回来，因为他们的字太差，我总是认错他们写的邮件地址。
Happy golden birthday! I can't wait to hear all about it when you get back.
金色生日快乐（年纪和出生那天的日子相同的生日）！我已经等不及听你回来后分享旅程了！
If mom can't be home when kids get back from school, she can leave a note with a voice and picture on the screen to tell them what there is to eat.
如果孩子们从学校回来时妈妈不能在家，她可以在屏幕上用声音和图片留下便条，告诉他们有什么吃的。
The goldfish showed that not only could they store information, they also had the ability to get it back as a later date.
金鱼证明了它们不仅能储存信息，还能在以后把信息找回来。
No, John will be back then, and he'll get me home.
约翰那时会回来，他会送我回家。
I had to leave the game at half time and rush back so you wouldn't get angry with me.
为了不让你生我的气，我不得不在中场休息时离开，然后赶回来。
The little boy rushed to the hospital and shouted happily to his uncle, "Uncle, I bought God back and you will get well soon."
小男孩冲到医院，高兴地对叔叔喊：“叔叔，我把上帝买回来了，你很快就会好起来的。”
Some short videos even sell bad products, but these sellers won't let you get your money back.
一些短视频甚至会售卖一些不好的产品，但这些卖家并不会让你把钱拿回来。
Without a boss waiting for you to get back from lunch, it can often be tempting to waste a few hours before returning to work.
在没有老板催你吃完饭要马上回来工作的情况下，你可能在回来工作之前已经浪费了好几个小时的时间。
Make it clear that you're going to go regardless of whether there's a job waiting when you get back.
让他们明白你一定要去——不论当你休假回来时是否还有这个职位在等着你。
"Scoot3," he said to me with a wink, "and come and see me when you get back." for.
“快去吧，”他对我眨眨眼说道，“回来后去找我。”
There's also a Company business card with his name and the title "Special Liaison," with the message, "This is what's waiting for you when you get back.
其中还有一张“公司”的名片，上面写着他的名字和职位“特别联络员”，还有一条信息，“这就是你回来时所能得到的好处。”
When you give someone your time, you are giving them a portion of your life that you'll never get back. Your time is your life.
因此当你付出时间给某人，乃是将你生命的一部分送给他，而那是绝对要不回来的，因为时间就是生命。
I would think that it would approach inifinity, and I would need to think about it and get back to you in terms of why we don't actually hit it and see something with an infinite wavelength.
我会认为波长会接近无穷大，而且我需要考虑一下,然后返回来告诉你,为什么我们没有说对,为什么我们没有看到,无穷大波长的东西。
In the old days, a designer working on an airplane wing handed a bunch of punch CARDS to the computer operator and waited a week to get back thousands of Numbers on fanfold paper.
那时候，一个设计飞机机翼的工程师会把一大堆穿孔卡片交给电脑操作员，等上一个星期才能拿回来成千上万的数字，而且是写在复写纸上的。
By the time you do get back, after a long stint abroad, the organization has changed so that there's no comparable job for you.
你为公司在海外打拼那么长时间，可等你回来的时候，公司已经发生了很大变化，并且没有适合你的工作岗位了。
But then suddenly they get yanked back, and they wake up, you know, in the hospital room.
但是突然他们被猛拽回来，然后他们在病房里，醒了过来。
They can also travel further from their spacecraft because, in an emergency, they can get back faster.
他们能够去往离太空船更远的地方，因为，在紧急情况下，他们能更快速地赶回来。
Ms Anderson: I'd like some fresh towels in the suite when I get back this evening.
安德森女士：我希望我晚上回来的时候房间里能有干净的毛巾。
'You'd better get back here, it looks like it's Benson,' Mr. Bridgefoot remembers being told.
布瑞志福特回忆说，孙子电话中告诉他，你最好回来，它看起来像是本森。
Ms Anderson:... oh, I can never find the light switch when I get back in the evening.
安德森女士：哦，我晚上回来的时候总也找不到灯的开关。
Ms Anderson:... oh, I can never find the light switch when I get back in the evening.
安德森女士：哦，我晚上回来的时候总也找不到灯的开关。
应用推荐