了解今日课堂：

1、Henry老师好：我有个疑问，关于图片这个单词graphics, image, picture用法的区别，我比较纠结image和picture，我查看了下image有形象，印象（比较抽象的概念），也有雕像，画像的意思，但是我发现有些老外（还是英国的）也用image表示图片的意思。我想问下，我们常说的电脑或手机的普通图片用picture好，还是image呢，感觉都是可以用。另外还有Graphics这个词，我查看了是偏向矢量图（例如AI软件制作），有个老外用这个词表示所有设计图（有些并不是矢量图），不知道是不是错的呢。谢谢老师！

2、我有个语法问题想请教一下Henry老师：关于 if…not 与 unless的区别和用法，在一些语法书说 unless不能用于虚拟语气。 但我看到 I couldn't have got to the meeting on time -unless I had caught anearlier train.有的语法书说 unless后不能加否定句等等....

总之，我觉得沒有一本书能把这两个词讲清楚了。所以我想请Henry老师帮忙解答一下，这两个词真正的区别和用法，非常感谢。

【听力文段】mp3

A NASA astronaut's lessons onfear, confidence and preparing for spaceflight

Welcome, Megan.

Hello, Pat, thank you forhaving me.

Let's go with the questionthat I think is probably coming up for many of us. This is unusual. Husband andwife, met during your training. And in the year that you got married, you bothflew into space, separately. You, on the Hubble Telescope mission and Bob onthe mission to construct the space station. And ironically, if your missionhad gone awry or needed help, Bob was assigned to be on therescue craft.

I just want to bring forward aquote from the SpaceX leader Gwynne Shotwell: “I'd like to point out that,you know, Megan is first and foremost an astronaut whenit comes to our perspective.”

Well, I did want to reachthrough the screen and high-five Ms Shotwell when she said that, I very muchappreciated that remark. You know, it has changed for me over the years, thefirst time I flew in space I was married. But I was not yet a parent. And bothmy husband and I came to NASA as single people. And we met and married, ofcourse, at NASA. It's a different thing to take on as a family that you'redoing this thing that's for yourself. It's also kind of for the greater good.The notion of exploration and discovery is something to engage in. And I thinkthat that example, you know, for my son to see that his parents are engaged inthis thing, that, yes, it takes us away from him. But these are importantthings to do.

And you were in high school,Megan, when the Challenger spacecraft tragically exploded and the whole worldconfronted the realities of the risk that you and your husband and other bravewomen and men are taking. I remember that moment. And I still hold mybreath every time during each and every launch. Sohow do you find the balance between knowing the risks are real and you'refeeling prepared enough to do what you have to do and what you want toaccomplish?

Well, the crux of it forus for feeling prepared and participating is really training. So we train ourway into that seat. You spend literally hundreds of hours preparing in everypossible way. We break down every system into bite-sized pieces,basically. We have these wonderful instructors who are professionalinstructors, basically. And they know exactly what it's going to take for us tolearn these systems inside and out. And so, sort of, one system ata time. And then they put all the systems together. And then they break everypossible thing that they can think of to break so that you have to, as a team,as a crew, solve these problems and work together to get through the situation.And the reason that they do that is not because they think those exact thingsare going to happen. It's to build you up. You prove to yourselfthat you have the ability to work when maybe some really terrible things arehappening and to make your situation better. And the thing that's going tohappen isn't necessarily going to be the specific one or even hundred differentscenarios that they've shown you. But you have worked and you have developedyour skills which will support you to kind of tackle anyproblem that you might have, not just as a crew in the ship. But now you'veworked with the whole team on the ground. And you know you're going to be ableto solve those situations working together.

【单词短语】

1. go awry

2. first and foremost

3. hold one’s breath

4. each and every

5. the crux

6. bite-sized pieces

7. inside and out

8. tackle

【地道美语，长句精练】

1. I'd like to point out thatMegan is first and foremost an astronaut

2. We break down every systeminto bite-sized pieces

3. It's to build you up.

【课堂纠音，上节连读】

1. Is anyone going to help heron her adventure?

2. What do you have in commonwith Harry Potter?

3. You’ll certainly see itagain