Install the Code2000 font to view the results.
Test passes if the order of characters and paragraphs and the angle of characters is the same.
ᠬᠤᠯᠤᠭᠠᠨᠠ ᠡᠨᠳᠡ ᠡᠨᠡ ᠭ᠋ᠠᠯ ᠴᠢᠷᠢᠭ ᠬᠠᠨᠠ
ᠤᠷᠲᠤ ᠡᠨᠳᠡ ᠡᠨᠡ ᠭ᠋ᠠᠯ ᠴᠢᠷᠢᠭ
Assertion: Setting writing-mode to tb-lr will cause Mongolian text to run vertically down the left size of a box, with upright characters, and wrap to the right, and cause paragraphs to flow to the right.
= means you should check that the test and reference graphic look the same. If not, check the instruction text.