Do you know the website where we can get questions and answers in English about many kinds of subjects for elementary school students?

I don't know of any individual website that does that, but here are some that I've used in the past for different things:

http://eslcafe.com/
The table of contents is down the left side, as well as across the top. If you click on Stuff for Students, you'll find several more links, mostly regarding the learning of English, but the bottom one (Student Forums) looks interesting.

https://www.englishclub.com/
I've mainly used this website to find good explanations for different English language topics, but you can see from the list on the left side, as well as many different links all over this homepage, there's lots more to this website than learning English!

And here are two others. I haven't checked these out in quite a while, though, so I'm not sure if you'll find them useful or not:
http://www.manythings.org/
and
http://a4esl.org/

Yes, there are several websites where you can find questions and answers in English for elementary school students. One popular website is called "Brainly." Here's how you can access it:

1. Open your web browser (such as Google Chrome, Mozilla Firefox, or Safari) on your computer or mobile device.
2. In the address bar, type "www.brainly.com" and press Enter.
3. Once the Brainly website loads, you will see a search bar in the center of the page.
4. Type your question or the subject you are looking for in the search bar and click the magnifying glass icon or press Enter.

Brainly is a platform that allows students to ask questions and get answers from other students and experts in various subjects. It covers a wide range of topics, including math, science, history, language arts, and more. The questions are geared towards elementary, middle, and high school students.

Remember to use this website responsibly and cross-verify the answers you find to ensure accuracy.