I tried to create a new WP_Query and show some of the latest posts inside a page without creating a page template, but the new WP_Query somehow failed to get any result.
I don’t know why.

Follow-up:
Alas, I finally get it working. I found using WP_Query inside a page with my Exec-PHP is practically impossible after tireless tries, and decided to go to page templates for solutions.
I think both of the two examples on multi-loops given on the WordPress Codex should work. However, inside their WP_Query class, a lot of global variables are used. This terrible scripting habit forces me to call wp_reset_postdata() after the inner loop. What’s more evil, the functions like the_title() also depends on those global variables. These code are something that no good programmer would ever write.
A little thing that has also confused me, is that the_post() does not output the content of the post as its name suggests to me. It only tells the WP_Query object to use this post. Could have given a better name to it…

For those interested, an example on bavotasan.com should be enough to guide you through. Just bear in mind that this would only work in page templates, plugins, and other code that are stored as files.