En outre, si on voudrait trouver un app dans Google Play, lequel est-ce qu'on choisirait? :)

Hey there! It's much easier to correct if you post this in your notebook! But I will try to help out here anyway. Michael Young was one of the most talented and influential sociologists in England. He was a man with a surprising combination of creative thought and practical activity (<although "practical activity" doesn't make sense. Can you try to describe what you're saying here so I can advise better?). However, for the general public, Young is rather famous as a Customers' Coalition founder, an organization which researches the quality range of consumer goods, from cars to razor blades. Young was born in Manchester in 1915. His father was an Australian violinist who later became a musical critic, and his mother was a teacher from Ireland. He lived in Australia until age 8, but he got an education in England, studying first in London, and then at Dartington Hall. While studying in school, he decided to become an architect and participated in a competition to design a cheap apartment home. Later, he decided to become a lawyer. He received a law degree, and although he never worked as a lawyer, his knowledge in law was enough to establish the Customers' Coalition.

The Stranger. Part 50

We waited until midnight, but the explosion didn't come. The night was cold. We talked while sitting by the bonfire.
"Well, I don't think anything is keeping us from returning to our world," Lisa said.
"I hope so. What are your plans for the future, if we manage to return?"
"I'm trying to forget about that. And you?"
"I'll remember the journey for a long time. [[There is a cause this situation happens to (with) us"]]? (Don't understand what you're trying to say. Sorry!)
"Exactly! But everything is more difficult than we can imagine. Are you sure you know where your home is?"
"What do you mean?" I asked.
"I'll tell you about that later."
"Well, I've heard it a hundred times. Will you remember me at the home world?" (<Not quite sure about context here. Is it called a "home world" or are you trying to say mother country maybe? It's not necessarily wrong! :))
"Our trouble starts when we return. I don't want to forget you, but we will walk for a long time"
"Desert souls," I spelled meaningfully.
"What?"
"Yes, desert souls. Our troubles just expect us." (<Also not quite clear what you mean by the second sentence.)
"I know what you mean. Yes, it will be hard" Lisa said...

Or "if all goes according to plan."

1.Your teacher is incorrect...EXCEPT in certain historical contexts, such as on a timeline (for example, "1809: Abraham Lincoln in born in Kentucky..."). The word "is" is present tense. It's also a state of being. Your friend's birth in Dallas occurred in the past. Period. 2. Both are correct, depending on context, as Paul said above. Note that you are more likely to hear "taught not to talk to strangers," and not "taught not to talk with a stranger." It's okay to say you talked with someone, or spoke with someone, but it's definitely much much more common in English to say you talked "to" someone. Plus, in English, it's extremely common to reference this "childhood lesson" as "talking to strangers" (in the plural). Hopefully my addition was helpful too.

I'll add that "family trash" and "playing facilities" don't sound natural in English. You would probably hear them phrased like this: 1. The children destroyed the facilities on the playground. (Or just "destroyed the playground" or "the structures on the playground") 2. The housewives left the trash in the street. OR The housewives left the family's trash in the street. OR The housewives left their trash/their family's trash in the street. (If there isn't any other context given beforehand)

In conversation, you always need to put "The" before a noun such as "sky." However, I will point out that poetic license (an English phrase describing the flexibility we give to authors, writers, poets, lyricists, etc when they create their works) would absolutely allow you to use simply "sky is grey" in certain situations, such as a haiku, in a song, or something like that, but you will very very rarely hear it.