It seems to me that they use a lot of uncommon words and grammar structures based on the answers to the questions that I have submitted in the past.
What Mohammed said. If you are advanced in English and just want to extend your vocabulary then why not? If your main goal is to improve in everyday conversations then maybe it's not the best idea. At least be ready to get some strange looks :-)
The Economist is generally a very good source of well written English. If you're wondering about the 'encloses' from yesterday, I guess that was just a 'glitsch'. As the description was about a product from Korea, it might have been an oddly translated phrase that nobody at The Economist got round to tidying up. Don't worry about it, and do carry on reading The Economist.
It depends on your stage in the language, and what you really wanna improve.for me i found that movies and series helped me a lot get used to the sounds and the daily expression native speaker ues
I think yes that is a bad idea but I think that is mroe painful to read chemistry or biology in english