Hi there!

Here are my corrections to your sentences.  I hope this is helpful, let me know if you have any questions about them!

Medical scientists have discovered (for medical discoveries we usually use 'have' - present perfect tense -  when they are new discoveries which are being reported.  For old discoveries we use normal past tense. 'Isaac Newton discovered gravity.  Also 'discovered' is better than 'found out'. 'Found out is better for less important things or non academic/scientific things) found out that girls who are (comes from 'be physically active')physically active when they are teenagers generally live longer (this is the preferred way to say this phrase in my opinion.  I have read many articles about health and living longer, and they all seem to prefer this phrase). extend their life span. The research was conducted on seventy five thousand women aged from forty to seventy. It was discovered that those girls who were doing a lot of exercises ('exercises' in plural talks about individual exercises, such as push-ups or squats.  If you are talking about any physical activity in general, we just say 'exercise')during their adolescence suffered less from life threatening diseases such as cancer and a heart stroke. heart disease. (you may also want to say strokes here, heart disease and strokes are two different health problems)Even a short exercise of 15 minutes has a great and positive effect on their health.

Hi there! Here are my corrections to your text. I hope this helps, let me know if you have any questions about them!

Sweetly ('sweetly' is an adverb with describes 'how' you do something, e.g. 'He smiled sweetly'.  Here you need to use sweet as an adjective to describe the taste of the cherries)cherries

Hi there, here are my corrections to your writing.  I hope this helps, let me know if you have any questions about them!

A particularly officious custom officer suspects(must be past tense because it is a story) suspected that the ('the' writer if we already know who the writer is)writer was trying to smuggle something through customs(we don't really use the word 'smuggler' as a noun anymore because it sounds quite old-fashioned.  We prefer to use the verb 'smuggle' in some form) to be a smuggler unless he could and wanted to unlock his suitcasea to check it.for checking. With While ('while' is used to talk about something that happened during another continuing action)carefully searching the case, the ('the' officer because it is a noun and it needs something before it 'a'/'the'/'his'/'her' etc. 'The' is the one we need because we know who the officer is)officer spotted a tiny bottle, and with delight a face brimming with delight and he sarcastically asked the writer is that a if it was a bottle of perfume.  (always a space after a full-stop)Although The writer explained that is this was his hair gel which he had made by himself, but the officer didn't believe that,  and so he tried to smell the bottle with writer's permission.  Finally, (always a space after a comma)he got the truth answer realized that the writer was telling the truth, and he let the writer him pass through.

Hi there, here are my corrections to your writing. I hope this is useful, let me know if you have any questions!

The writing is really good, but the next level is to start joining sentences together to help the writing flow better.  A good way to join some sentences together is to use some phrases I have used in the corrections:

Diary, May 7th Sunday May 7th

In the evening (no comma needed) I went to shopping and then (joins two short sentences to help it flow)I made dinner.  I made beef and burdock dishes and potato dishes, which (joins two short sentences to help it flow).They were easy to make and also tasty.  I put the pictures of the dishes on Instagram.  After I finished taking took a bath before doing(joins two short sentences to help it flow)I did 100 sit-ups. I am going to sleep soon.

Hi There! Here are my corrections and some suggestions on how to phrase things differently, let me know if you have any questions about them!

Toxic Parents

Hi there! Here are my corrections, let me know if you have any questions about them!

Today I ('I' is always a capital letter even in informal writing.  Some people use a small I when writing informally, but it would still be considered incorrect)saw a video clip on Youtube which was recorded 2 years ago . Dr. Han, a Korean roboticist, explained that after the ('the' because people know about it)Fukushima nuclear accident, people realized that the development of humanoid robots was futile in reality because robots couldn't even go up the ladders to repair a nuclear generating station. People needed to put themselves in danger to get it fixed, one of them was exposed to radioactive rays which proved fatal / and he died as a result. it caused him to death. America's Defence Advanced Research Projects Agency (DARPA) came up with an idea of holding the DARPA Robotics Challenge (DRC). They set up some missions for the challenge, robots had to where robots should drive cars, open doors, go up the ladders and use tools to solve problems spontaneously in a catastrophic situation. Dr. Han had an interview on TV before they had the finals. They started with over 200 teams from all over the world and ranked finished 9th in the first round. While I was writing this, I started to wonder who won what the result of the challenge. I found out that the other team from Korea won the first prize and it got gave me goosebumps :0. I had (past perfect because this happened before you found out that a Korean team won. You are going further back into the past)expected the Japanese team to win the competitionmust have won this game. Anyway, Robots with advanced technology will keep us from doing the tasks that can spare humans from carrying out tasks that could possibly prove fatal, possibly take our life though there are pros and cons in to consider with this issue. Some worry that robots will take our jobs, but (we don't usually start sentences with 'but', better to put a comma here)did the jobs that we have now even exist 200 years ago? I think it's all a natural transformation of an ecosystem. We should make the strike a (we always use 'strike a balance')balance and prepare for dramatic change ahead as of us while technology develops at a dizzying pace. I am excited to see what will happen!